Misfire, Running Rich

[Donf]

To refresh my truck's info since I know no one would remember;
'99 2WD, 4 Door LT, 161,000 miles
Owned since new, taken well care of overall. Didn't drive it for about 4 years or so until last year.
Historical issues - intake gasket replaced twice < 20,000 miles.
New plugs, wires, cap/rotor , 1500 miles ago with 4 bottles of Techron about that time.

Before and after I replace the ignition components I was throwing P0300's but evry time I had some kid at an auto parts store read them it would vary (300, 302, 308, 300, 304 etc).
After a while - and all that Techron - the Check engine light went away and all seemed good. But then, it returned.
So, I boughta$60 OBD scanner and now I consistently get P0300 (Random misfire)and P0172 (Bank 1 rich). Nothing else and I've read them over 5 days and get the same 2 codes.

Idles a bit rough, seems to smooth out at with a bit of throttle, runs reasonably well, but at highway speeds if I "punch it" it seems to miss, nothing horrible but power is definitely down. Gas odor at exhaust pipe.

Looking around the internet it seems there are very many possibilities. I'd naturally like to narrow it down, if possible.

I would very much appreciate any help, I haven't worked since the March 15 Covid unpleasantness started and I have fixed everything else around the house, learned lots of new recipes, watched movies I never would have sat through before, and learned how to cut my own hair....well!

Please help!

 

[exp500]

Can your scanner monitor live data? Might be worth a run to check and point you in a good direction.
Otherwise, cap/rotor/wires suspect if not Delco. Try Swapping or tightening coil wire.
Check for vacuum leaks, spray can of carb cleaner.
Let us know what you find.

 

[OR VietVet]

First: If you want to always have your rig info shown so you don't have to remember to do it with each post, put it all in your signature and will show with each post you make. Here is some info that may help you diagnose the problem. Afterall, you have nothing but time to do it:

What Does the P0172 Code Mean?
Diagnostic trouble code (DTC) P0172 stands for “Fuel System Too Rich (Bank 1)”. Your car’s computer will set the code when it determines that there’s too much fuel (or too little oxygen) in the engine’s air-fuel mixture. The bank 1 portion of the code indicates that the problem is concentrated on the side of the engine that includes the #1 cylinder (only applies to engines with a ‘V’ or flat configuration).

Ideally, combustion engines should burn a fuel mixture of 14.7:1. This means there should be 14.7 parts air and 1 part fuel in the mixture. A drop in the supply of air would result in a rich mixture while an increase would make it lean. The computer determines the air-fuel ratio by monitoring the upstream oxygen sensor/s.

But before anything else, anyone who wants to understand this code should first know what fuel trim is and why it matters.

What is Fuel Trim?
Fuel trim is the fuel mixture adjustment that your car’s primary computer, which is often referred to as the powertrain control module (PCM), makes to balance out the supply of fuel and air. If you check your vehicle with a scan tool, the fuel trim is usually displayed as a percentage.

In order for the PCM to determine if the mixture is rich or lean, the oxygen sensor must accurately read your engine’s fuel trim.

There are two types of fuel trim values in your car: short term and long term. Short-Term Fuel Trim or STFT is the value by which your engine is currently operating. It can suddenly fluctuate depending on factors like load and speed.

Long-Term Fuel Trim (LTFT), on the other hand, is based on your car’s average fuel mixture over a predetermined period of time.

The proper LTFT values should read around 0 percent and can go up to 8 percent. Any values beyond 10 or negative 10 means there’s a problem. When the LTFT drops between negative 20 and 25, code P0172 and/or P0175 will likely be set.

What are the Possible Causes of the P0172 Code?
Like any other OBD-II code, a P0172 can be caused by a variety of problems. In other words, there is no easy way to pinpoint what’s causing the problem other than examining the critical parts responsible for maintaining the right fuel mixture.

Here are the different possible reasons why you’re getting the engine code P0172:

• A leaking fuel injector
• Excessive fuel pressure due to restriction along the fuel return line or a faulty fuel pressure regulator
• Filthy air filter
• Restrictions somewhere in the air intake system
• Clogging due to buildup or physical damage in these exhaust components: catalytic converter, exhaust pipe, and muffler
• Faulty O2 sensor
• Exhaust leak
• Problems with other sensors (e.g., coolant temperature sensor, mass airflow sensor)
• Circuit issues, such as loose connections and damaged wiring
• Issues with the PCM, such as software in need of an update

What are the Common Symptoms of the P0172 Code?
A rich fuel mixture can cause your engine to consume more fuel. Apart from that, the underlying issues could cause damage to your engine.

Your exhaust system is also at risk as unburnt fuel reaching the exhaust lines can combust and damage parts like the catalytic converter.

To avoid this kind of headache, look out for these symptoms:

• Illuminated check engine light
• Lack of engine power
• Bad idling behavior
• Engine hesitations
• Misfiring
• Strong fuel odor from the exhaust or inside the cabin
• Poor fuel economy

How to Diagnose the P0172 Code
As outlined above, there are many potential causes for the OBD-II code P0172. Therefore, diagnosing the exact issue that is triggering the trouble code can be difficult.

This video can help too:

How to Fix the P0172 Code
There are many ways to fix a code P0172, but it would depend on the exact cause. You may end up simply needing to clean a component, but in some cases, you would likely need to replace something. Therefore, there isn’t a “magic bullet” fix for the issue. You’ll need to diagnose the code accurately, as outlined above, then perform any necessary repairs.

And of course, remember that all vehicles are different. When troubleshooting and repairing OBD-II trouble codes, make sure to consult the factory repair information for your application.

Repair manuals, such as those from Chilton, are useful, but an ALLDATA subscription is even better. ALLDATA has single-vehicle subscriptions for DIYers that provide detailed factory repair information.

 

[Donf]

Can your scanner monitor live data? Might be worth a run to check and point you in a good direction.
Otherwise, cap/rotor/wires suspect if not Delco. Try Swapping or tightening coil wire.
Check for vacuum leaks, spray can of carb cleaner.
Let us know what you find.

I think so, I'll try and figure out how to do it.
All the new ignition components are Delco, I tried to get the part numbers that GM recommended. Fortunately, I have a can of card cleaner sitting on my shelf. Glad to have a reason to use it, I cleaned my leaf blower's carb last month - not a good idea, it works fine now but that means I have to blow leaves (I have six 55 year old oak trees in my yard, that's a lot of leaves).

 

[Donf]

Thanks PNWVietVet,
I recently 'discovered' fuel trim. I'm trying to figure it out. I'll try and do what I can, I knew the list would be extensive and was hoping the two codes together would narrow it down. Would a bad O2 sensor throw it's own code? Or a bad cat?

 

[OR VietVet]

The front O2 sensor can throw it's own code and it did on my 05 Z71 about a week ago and it caused a rough idle at stops and mainly in gear under a load. The sensor was monitored and saw it completely shut down, it is supposed to be constantly switching within a certain parameter. Replaced it and problem was solved. A rear O2 sensor can throw a code that could indicate a bad sensor or a bad catalytic converter.

The front sensor is reading what is coming into it out of the exhause system. The rear sensor is monitoring how efficient the catalytic converter is.

 

[Donf]

Can your scanner monitor live data? Might be worth a run to check and point you in a good direction.
Otherwise, cap/rotor/wires suspect if not Delco. Try Swapping or tightening coil wire.
Check for vacuum leaks, spray can of carb cleaner.
Let us know what you find.

Is this the "Live Data"
*******************************DTC*********************************

VIN:

DTC_TYPE: Current DTCs ($03)

DTC_NUM: 2

PROTOCOL: J1850 VPW

LANGUAGE: English



P0172 System Too Rich Bank 1


P0300 Random/Multiple Cylinder Misfire Detected



*******************************DTC*********************************

VIN:

DTC_TYPE: Pending DTCs ($07)

DTC_NUM: 2

PROTOCOL: J1850 VPW

LANGUAGE: English



P0172 System Too Rich Bank 1


P0300 Random/Multiple Cylinder Misfire Detected



****************************LIVE DATA******************************

VIN:

PROTOCOL: J1850 VPW

LANGUAGE: English



Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -18.0%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.9inHg


Engine RPM 650/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 20.5


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 1.0lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.900V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.755V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.940V


Short Term Fuel Trim (B2-S1) -18.8%


Oxygen Sensor Output Voltage (B2-S2) 0.095V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -21.1%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.9inHg


Engine RPM 622/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 25.5


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 1.0lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.905V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.735V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.495V


Short Term Fuel Trim (B2-S1) -21.1%


Oxygen Sensor Output Voltage (B2-S2) 0.095V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -20.3%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 10.2inHg


Engine RPM 619/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 20.0


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 0.9lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.870V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.760V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.830V


Short Term Fuel Trim (B2-S1) -21.1%


Oxygen Sensor Output Voltage (B2-S2) 0.095V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -21.9%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.9inHg


Engine RPM 652/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 27.0


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 0.9lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.915V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.755V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.215V


Short Term Fuel Trim (B2-S1) -18.0%


Oxygen Sensor Output Voltage (B2-S2) 0.045V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -18.8%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.6inHg


Engine RPM 641/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 23.0


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 1.0lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.870V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.740V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.165V


Short Term Fuel Trim (B2-S1) -20.3%


Oxygen Sensor Output Voltage (B2-S2) 0.115V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -20.3%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.9inHg


Engine RPM 637/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 27.0


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 1.0lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.890V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.720V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.085V


Short Term Fuel Trim (B2-S1) -20.3%


Oxygen Sensor Output Voltage (B2-S2) 0.055V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -18.0%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 10.2inHg


Engine RPM 613/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 21.5


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 0.9lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.890V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.740V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.930V


Short Term Fuel Trim (B2-S1) -19.5%


Oxygen Sensor Output Voltage (B2-S2) 0.105V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -20.3%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.9inHg


Engine RPM 673/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 24.5


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 0.9lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.905V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.765V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.940V


Short Term Fuel Trim (B2-S1) -21.1%


Oxygen Sensor Output Voltage (B2-S2) 0.095V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -18.8%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.9inHg


Engine RPM 618/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 18.0


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 0.9lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.735V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.625V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.360V


Short Term Fuel Trim (B2-S1) -18.8%


Oxygen Sensor Output Voltage (B2-S2) 0.095V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF



******************************FREEZE*******************************

There's no recorded data!


****************************LIVE DATA******************************

VIN:

PROTOCOL: J1850 VPW

LANGUAGE: English



Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -18.0%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.9inHg


Engine RPM 650/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 20.5


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 1.0lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.900V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.755V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.940V


Short Term Fuel Trim (B2-S1) -18.8%


Oxygen Sensor Output Voltage (B2-S2) 0.095V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -21.1%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.9inHg


Engine RPM 622/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 25.5


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 1.0lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.905V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.735V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.495V


Short Term Fuel Trim (B2-S1) -21.1%


Oxygen Sensor Output Voltage (B2-S2) 0.095V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -20.3%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 10.2inHg


Engine RPM 619/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 20.0


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 0.9lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.870V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.760V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.830V


Short Term Fuel Trim (B2-S1) -21.1%


Oxygen Sensor Output Voltage (B2-S2) 0.095V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -21.9%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.9inHg


Engine RPM 652/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 27.0


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 0.9lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.915V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.755V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.215V


Short Term Fuel Trim (B2-S1) -18.0%


Oxygen Sensor Output Voltage (B2-S2) 0.045V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -18.8%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.6inHg


Engine RPM 641/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 23.0


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 1.0lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.870V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.740V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.165V


Short Term Fuel Trim (B2-S1) -20.3%


Oxygen Sensor Output Voltage (B2-S2) 0.115V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -20.3%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.9inHg


Engine RPM 637/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 27.0


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 1.0lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.890V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.720V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.085V


Short Term Fuel Trim (B2-S1) -20.3%


Oxygen Sensor Output Voltage (B2-S2) 0.055V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -18.0%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 10.2inHg


Engine RPM 613/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 21.5


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 0.9lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.890V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.740V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.930V


Short Term Fuel Trim (B2-S1) -19.5%


Oxygen Sensor Output Voltage (B2-S2) 0.105V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -20.3%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.9inHg


Engine RPM 673/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 24.5


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 0.9lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.905V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.765V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.940V


Short Term Fuel Trim (B2-S1) -21.1%


Oxygen Sensor Output Voltage (B2-S2) 0.095V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -18.8%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.9inHg


Engine RPM 618/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 18.0


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 0.9lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.735V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.625V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.360V


Short Term Fuel Trim (B2-S1) -18.8%


Oxygen Sensor Output Voltage (B2-S2) 0.095V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF



******************************FREEZE*******************************

There's no recorded data!


*******************************DTC*********************************

VIN:

DTC_TYPE: Current DTCs ($03)

DTC_NUM: 2

PROTOCOL: J1850 VPW

LANGUAGE: English



P0172 System Too Rich Bank 1


P0300 Random/Multiple Cylinder Misfire Detected



*******************************DTC*********************************

VIN:

DTC_TYPE: Pending DTCs ($07)

DTC_NUM: 2

PROTOCOL: J1850 VPW

LANGUAGE: English



P0172 System Too Rich Bank 1


P0300 Random/Multiple Cylinder Misfire Detected



******************************FREEZE*******************************

There's no recorded data!


******************************FREEZE*******************************

There's no recorded data!


****************************LIVE DATA******************************

VIN:

PROTOCOL: J1850 VPW

LANGUAGE: English



Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -18.0%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.9inHg


Engine RPM 650/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 20.5


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 1.0lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.900V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.755V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.940V


Short Term Fuel Trim (B2-S1) -18.8%


Oxygen Sensor Output Voltage (B2-S2) 0.095V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -21.1%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.9inHg


Engine RPM 622/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 25.5


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 1.0lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.905V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.735V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.495V


Short Term Fuel Trim (B2-S1) -21.1%


Oxygen Sensor Output Voltage (B2-S2) 0.095V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -20.3%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 10.2inHg


Engine RPM 619/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 20.0


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 0.9lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.870V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.760V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.830V


Short Term Fuel Trim (B2-S1) -21.1%


Oxygen Sensor Output Voltage (B2-S2) 0.095V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -21.9%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.9inHg


Engine RPM 652/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 27.0


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 0.9lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.915V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.755V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.215V


Short Term Fuel Trim (B2-S1) -18.0%


Oxygen Sensor Output Voltage (B2-S2) 0.045V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -18.8%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.6inHg


Engine RPM 641/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 23.0


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 1.0lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.870V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.740V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.165V


Short Term Fuel Trim (B2-S1) -20.3%


Oxygen Sensor Output Voltage (B2-S2) 0.115V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -20.3%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.9inHg


Engine RPM 637/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 27.0


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 1.0lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.890V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.720V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.085V


Short Term Fuel Trim (B2-S1) -20.3%


Oxygen Sensor Output Voltage (B2-S2) 0.055V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -18.0%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 10.2inHg


Engine RPM 613/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 21.5


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 0.9lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.890V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.740V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.930V


Short Term Fuel Trim (B2-S1) -19.5%


Oxygen Sensor Output Voltage (B2-S2) 0.105V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -20.3%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.9inHg


Engine RPM 673/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 24.5


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 0.9lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.905V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.765V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.940V


Short Term Fuel Trim (B2-S1) -21.1%


Oxygen Sensor Output Voltage (B2-S2) 0.095V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF


Fuel system 1 status CL


Fuel system 2 status CL


Calculated LOAD Value 3.1%


Engine Coolant Temperature 188F


Short Term Fuel Trim - Bank 1 -30.5%


Long Term Fuel Trim - Bank 1 -18.0%


Short Term Fuel Trim - Bank 2 -18.8%


Long Term Fuel Trim - Bank 2 -18.0%


Intake Manifold Absolute Pressure 9.9inHg


Engine RPM 618/min


Vehicle Speed 0mph


Ignition Timing Advance for #1 Cylinder 18.0


Intake Air Temperature 51F


Air Flow Rate from Mass Air Flow Sensor 0.9lb/min


Absolute Throttle Position 0.0%


Oxygen Sensor Output Voltage (B1-S1) 0.735V


Short Term Fuel Trim (B1-S1) -30.5%


Oxygen Sensor Output Voltage (B1-S2) 0.625V


Short Term Fuel Trim (B1-S2) 99.2%


Oxygen Sensor Output Voltage (B2-S1) 0.360V


Short Term Fuel Trim (B2-S1) -18.8%


Oxygen Sensor Output Voltage (B2-S2) 0.095V


Short Term Fuel Trim (B2-S2) 99.2%


OBD requirements OBD2


Auxiliary Input Status OFF

 

[exp500]

What I notice are a few misfires AND fuel trims. Try to eliminate misfires, or make them move to different cylinder. Swap or tighten coil wire, Swap spark plugs on misfiring cylinder(s), Spray intake with carb cleaner, listen for change in engine. Do you have a fuel pressure Guage?

 

[exp500]

You also may be able to pick a few of those PIDs and display/log live data. I prefer to eliminate ignition faults before fuel faults for a better direction on fuel faults.

 

[Donf]

You also may be able to pick a few of those PIDs and display/log live data. I prefer to eliminate ignition faults before fuel faults for a better direction on fuel faults.

Thank you!
What's a PID?
I can't see which cylinder(s) is misfiring (from the way it feels I think it is one, or only one at a time)
Is a constant MAO pressure or 9.9 sounding right or is that low?

Re Fuel Faults - I have the original fuel filter, I am hesitant to change anything that isn't broke at this time however. Opinion?

 

[exp500]

PID is a description number for each thing monitored. Go to the website for your scanner and look for Advanced or extra or new PIDs- They might not even call them PIDs. Try to learn it a little more, you have alot shown, but if you chose to monitor cylinders 1-8 missfires individually for instance, then a misfire at the coil would be equally distributed among all 8. A spark plug on #2 would be trouble code P0302. for #5 P0305 , trouble code P0300 missfire. Counts have to reach a threshold value to set as specific. P0300 VS P0301
MAO? Communist in your motor? MAP manifold air pressure 9.9 under light load ok. 14-19 inches no load.
Do you have a fuel pressure guage? Monitor fuel pressures when it misses. Change your fuel filter EVERY YEAR. Change it now.
It got better with Techron- A clue.
What I think- you posted above was live but a snapshot of everything monitored.
Techron and fuel filter I would do now. Fuel pressure gauge As soon as you can, Website or Utube for scanner.

 

[Donf]

Will do, thanks.
Honestly, last time I worked on this stuff EGR valves and smog pumps were state of the art and carburetors and points were the rule. But I can learn.

 

[wjburken]

smog pumps were state mandated

Fixed Your Post

 

[Donf]

PID is a description number for each thing monitored. Go to the website for your scanner and look for Advanced or extra or new PIDs- They might not even call them PIDs.

Website predictably useless

Try to learn it a little more, you have alot shown, but if you chose to monitor cylinders 1-8 missfires individually for instance, then a misfire at the coil would be equally distributed among all 8. A spark plug on #2 would be trouble code P0302. for #5 P0305 , trouble code P0300 missfire. Counts have to reach a threshold value to set as specific. P0300 VS P0301

I think I have learned a bit just playing with if for an hour. Cannot isolate individual cylinders but P0300 is constant, cannot get any other misfire code now.

MAO? Communist in your motor?

He seems to have left for the White house

MAP manifold air pressure 9.9 under light load ok. 14-19 inches no load.

See below.

Do you have a fuel pressure guage? Monitor fuel pressures when it misses. Change your fuel filter EVERY YEAR. Change it now.

No, recommendations?

It got better with Techron- A clue.
What I think- you posted above was live but a snapshot of everything monitored.
Techron and fuel filter I would do now. Fuel pressure gauge As soon as you can, Website or Utube for scanner.

Got an AC Delco Filter, changed it. No changes.
Sprayed a bit of carb cleaner around some vacuum connections (less than I thought would be there) but no change in idle.
Removed air cleaner and noticed no changes either.

I cannot copy and paste the graphic data, should have asked that specifically I guess.
Instead I have made use of a process utilizing paper and pencil (learned that in school right before slide rule practice). Maybe it will help.

Calculate LOAD Value
Idle = 2.9 to 4.3
1500 RPM = 9.0

Intake Manifold Absolute Pressure
Idle = 9.9 to 10.2

Spark Advance
Idle = 20 to 26 degrees
1500 RPM = 28 degrees
2000 RPM = 31 degrees

MAF
Idle = .9 lb/min
1500 RPM = 2.4 lb/min


Absolute Throttle
Idle = 0.0 to 0.4%
1500 = 4.7%

Short Term Fuel Trim
B1
Idle = -30.5, Constant
1500 RPM = Rose to -20 to -30 then dropped to -30
B2
Idle = -25 to -7, Avg -10.2
1500 RPM = Rose to -20 to -30 then dropped to -10.2

Long Term Fuel Trim
B1 and B2
Idle = -18
1500 RPM = Rose then dropped to -18 but B2 returned slower

O2 Output Sensor
B1S1
Idle = .88 to .91
1500 RPM = .15 to .79

B1S2
Idle = .9 to .94
1500 RPM = .07

B2S1
Idle = .065 to .91
1500 RPM = .5 to .8

B2S2
Idle = .04 to .1
1500RPM = .05 to .06

Found a graph with all 4 fuel trims but with sensor
designations

All at idle

Min Max
------ ------
B1S1 -30.5 -30.5
B1S2 99.2 99.2
B2S1 -23.4 -18
B2S2 99.2 99.2

At 1500 RPM B1S1 -20 to 25
B1S2 99.2
B2S1 -14 to -18
B2S2 99.3

Also found a button that said " Check Evap System", It said FAILED, but no code shows up. Never has either.



So, does that show anything useful? Bad Cat? Bad sensors? Both? Neither?

Thanks

 

[79jasper]

Take a look at this video. (Yes truck in video is a 01, but I think it still applies to your engine)

Sent from my SM-G988U using Tapatalk

 

[Squirrelsmith]

Not that my story has anything to do with your condition but i was running lean, missfiring etc and it turns out my 1 year old msd cap and rotor had gone bad. Replaced with a ac delco and runs fine now

 

[exp500]

On your original snapshot scan, fuel trims looked Hi, I was hoping by live data you could narrow down the P0300 to a cylinder or bank. Find a fuel perssuse guage, ( harbor freight, amazon, craftsman) $30-50. Get a long fuel hose so it can stick out rear of hood where you can see it. You want 58# minimum. let us Know what the key on eng off press is, running pressure, and when it it missing what pressure is. I was trying to eliminate Ignition before fuel misses. Seems easier for me to diagnose in that fashion. When the Intake gaskets done, was the Spider replaced? Upgraded? On Ignition, Distributor cap should be Delco or United DCR 820X only. And trere were some Chineese Delco plugs for a year or two that fail early. Inside of dist look at wires to cam sensor rubbing on bottom of dist. Plug wires /coil wire suspect also. Last is Coil failure when hot, but usually that fails completely. Same with ICM.
Try more live scans monitoring PO301- PO308 ,Fuel trims, see if it is just one or two acting up. You are getting close to a resolution .

 

[Donf]

Got the pressure gauge.
Engine running - a bit over 50 psi
Key on, Engine off - jumps up to a hair over 50 then drops over 20-30 seconds to near 0. Stops a second or 2 around 20.
Can't tell a difference when it is missing.
Notice a few things, the cement near the tailpipe is black and looks like liquid is coming out of the pipe(drops) I can't smell at all and didn't have a match handy to test if it is flammable or not.

 

[Tonyrodz]

Got the pressure gauge.
Engine running - a bit over 50 psi
Key on, Engine off - jumps up to a hair over 50 then drops over 20-30 seconds to near 0. Stops a second or 2 around 20.
Can't tell a difference when it is missing.
Notice a few things, the cement near the tailpipe is black and looks like liquid is coming out of the pipe(drops) I can't smell at all and didn't have a match handy to test if it is flammable or not.

That liquid is most likely condensation--water, which is normal.

 

[Fless]

Got the pressure gauge.
Engine running - a bit over 50 psi
Key on, Engine off - jumps up to a hair over 50 then drops over 20-30 seconds to near 0. Stops a second or 2 around 20.
Can't tell a difference when it is missing.
Notice a few things, the cement near the tailpipe is black and looks like liquid is coming out of the pipe(drops) I can't smell at all and didn't have a match handy to test if it is flammable or not.

I'm not all that familiar with the OBS gen, but it seems to me that the fuel pressure leakdown is pretty fast. That would indicate a leaky injector or a bad fuel pressure regulator, something like that. Really just a guess on my part.