Torque app. O2 sensor data - can someone decipher?

[Charlie207]

Here are four screenshots while driving home the other day. 30 minutes of driving.

1st image is at idle (after 30 mins of driving)

2nd image is steady cruising at 35mph.

3rd & 4th images are cruising @75mph on the interstate.

It's clear the O2 sensors (left bank vs. right bank) aren't reporting the same voltages, and I'm assuming the left sensors are the ones shown out of whack. Trying to understand what I'm seeing.

Bad injectors, bad spark plugs/cables/coil(s), bad O2 sensors, cats....?

 

[gooffeyguy]

Your forward O2 sensor voltage should be jumping up and down like they're showing, if they weren't they'd be getting lazy and would probably be needing replacement.

Looking at the way you have this dashboard setup, it seems you have Bank 1 on the left and Bank 2 on the right, but your Bank 2 sensor 1 is on the left (second graph down) and Bank 1 sensor 2 is top graph on the right.

O2 1x1 = bank 1 sensor 1 (upstream)
O2 1x2 = bank 1 sensor 2 (downstream)
O2 2x1 = bank 2 sensor 1
O2 2x2 = bank 2 sensor 2

 

[Charlie207]

Your forward O2 sensor voltage should be jumping up and down like they're showing, if they weren't they'd be getting lazy and would probably be needing replacement.

Looking at the way you have this dashboard setup, it seems you have Bank 1 on the left and Bank 2 on the right, but your Bank 2 sensor 1 is on the left (second graph down) and Bank 1 sensor 2 is top graph on the right.

O2 1x1 = bank 1 sensor 1 (upstream)
O2 1x2 = bank 1 sensor 2 (downstream)
O2 2x1 = bank 2 sensor 1
O2 2x2 = bank 2 sensor 2

The orientation got all messed up when I shrank the O2 sensor size and added fuel trim to the screen. Good catch... I was doing this while waiting in line at my kid's school, and just now realized it.

 

[Charlie207]

Does this orientation make more sense, if I was trying to represent the sensor location from the perspective of looking straight down at my chassis from up above?

And, you're also saying those readings look normal?

I assumed BlackBear would have mentioned something during the tuning process if they noticed any wonky readings.

 

[gooffeyguy]

Yes, looks pretty normal.
Blackbear would normally tell you if something looks off while looking at the logs for tuning, and suggest fixing the problem before creating the tune for it.

 

[Fless]

View attachment 350062

Does this orientation make more sense, if I was trying to represent the sensor location from the perspective of looking straight down at my chassis from up above?

And, you're also saying those readings look normal?

I assumed BlackBear would have mentioned something during the tuning process if they noticed any wonky readings.

The orientation as shown now (much easier to comprehend) would be as it looks from the driver's seat (lefthand drive). Bank one is driver's side; bank 2 is passenger side.

I didn't see anything obvious; the movement of either bank's S1 may differ a bit from the other side. If you add your STFT and LTFT numbers for one bank together, ideal would be close to zero. Typically anything within +/-10% total wouldn't be alarming. I think the money light is triggered at +/-25%.

 

[swathdiver]

Here are four screenshots while driving home the other day. 30 minutes of driving.

1st image is at idle (after 30 mins of driving)
View attachment 350044

2nd image is steady cruising at 35mph.
View attachment 350045

3rd & 4th images are cruising @75mph on the interstate.
View attachment 350046View attachment 350047

It's clear the O2 sensors (left bank vs. right bank) aren't reporting the same voltages, and I'm assuming the left sensors are the ones shown out of whack. Trying to understand what I'm seeing.

Bad injectors, bad spark plugs/cables/coil(s), bad O2 sensors, cats....?

Operating as it should. You might have a slight vacuum leak, try re-torqueing the intake bolts, your Long Term Fuel Trims at idle are "slightly" high.

 

[Charlie207]

Intake manifold or intake pipe?

 

[swathdiver]

Intake manifold or intake pipe?

The intake manifold. Watching my trims for the last 4 plus years, they've been creeping up but do go down a little when we re-torque the intake manifold bolts but soon start creeping up again. Going to change them out when the weather cools. The other trucks sits at zero at idle and while running, nice and tight, everything running 100%.

 

[Charlie207]

You know the torque spec off the top of your head, or have an online resource for the FSMs?

 

[swathdiver]

You know the torque spec off the top of your head, or have an online resource for the FSMs?

44 Inch pounds the first pass and 89 inch pounds on the second pass.

FSMs? I have an online subscription to AllDataDIY.

 

[Fless]

You know the torque spec off the top of your head, or have an online resource for the FSMs?

Note that the torque specs @swathdiver gave are in INCH lbs, not foot lbs.

 

[Charlie207]

View attachment 350152
44 Inch pounds the first pass and 89 inch pounds on the second pass.

FSMs? I have an online subscription to AllDataDIY.

Thanks!

FSM = Factory Service Manual. All Nissan FSMs used to be available online for free, so I had three of them saved on my computer in the past (2004 Pathfinder, 2004 Xterra, 2005 Armada). At some point Nissan's legal department decided that it was time to remove free access to the FSMs, so they were all given copywrite warnings whereever they were hosted. Pretty dumb. Anyways, the internet never forgets (e.g. The Pirate Bay).


And, yeah.... lb/in vs lb/ft could be a big mistake.

 

[swathdiver]

Thanks!

FSM = Factory Service Manual. All Nissan FSMs used to be available online for free, so I had three of them saved on my computer in the past (2004 Pathfinder, 2004 Xterra, 2005 Armada). At some point Nissan's legal department decided that it was time to remove free access to the FSMs, so they were all given copywrite warnings whereever they were hosted. Pretty dumb. Anyways, the internet never forgets (e.g. The Pirate Bay).


And, yeah.... lb/in vs lb/ft could be a big mistake.

A few years ago someone found the shop manuals online for these trucks for free. I cannot remember but we talked about it alot then!

I bought a download from a guy on Ebay, SeriousCTBuyer and other guys on here used him and others on Ebay to get better manuals for less money. I also use my online subscription to AllDataDIY. They have a new one that is more interactive which I will purchase when my 5 years is up in 2022 and see what it is like. Been using them since 2006.

 

[gpracer1]

So are you asking for info about O2 sensors or is there an issue with your vehicle?
I used this same live graph to finally pinpoint rough idle, high idle hangs on decel and lean codes on my C5 vette by watching these O2s going up and down at idle then spraying some propane from a torch (not lit) around the injectors. Graph shot straight up when hit with propane. Turns out after 170,000 miles the injector orings were hard as glass and leaking air into the manifold. $10 later and its a new car again after years of trying to figure it out.