Please help with P1153

[mikez71]

yes the temp gauge read 210...when I let it idle it was after a 5-8 minute drive...anyway to tell if its in closed loop?

Your scanner should show it somewhere..
Could be it happens on startup check? (in case it's a slow heater, might be worth logging cold start readings)
By no means excluding warmed up readings.

GM, NTK or Denso seem to be the only recommended brands..
(Thought someone installed a Denso and it was NG?)
Here some variations of Denso... https://www.tahoeyukonforum.com/threads/gm-o2-sensor.153771/post-1980067)

 

[West 1]

Denso is usually a quality brand.

Mike you mentioned your O2 reads differently at times. Any time you hit the power brakes you pull vacuum and the sensors reading will be way off of normal. If you get bored try pumping the brake pedal while watching the O2 sensors. It is a good test to see if they are adjusting as they should. Fuel trims will change when you do the brake pump test also.

As your reading the O2 sensors start quickly pumping the brakes, down and full up many times. The sensors should fall and as you stop pumping should come back to normal over the next minute or so.

 

[mikez71]

Interesting, I will try that next time!
Tried this morning @West 1 !

First a cold start, Short Term fuel trims start moving about 16 seconds in, ect was 56F.
Took about 28seconds before O2's oscillate normally..

I wouldn't have thought that manifold pressure would change enough to affect o2 readings.
But you're right of course, ECT 90F, MAP goes from 36kpa to 39pa, O2's peg lean.

second time just a few seconds later, ECT 95F, 32kpa to 39kpa while pumping brakes.
(Yellow squiggles is pedal position) STFT goes upto around +20! (after 10 -11 pumps)

WOT the o2s pegged rich of course.

 

[Fless]

When you see STFT values and they're switching, it's in closed loop (CL). Not to say that it can't go in and out of CL, but if the O2 heaters are working it should hit CL relatively quickly and stay in CL.

 

[mikez71]

Forgot to log if closed loop..
BUT if looking at the maps in tune, a startup coolant temp of 56degF should not activate closed loop until coolant reaches approx 105degF..
('08 has 102 instead of 95 in the table below, few other small changes between '08 vs '12)

(And I was at 90-95degF ECT during the brake pedal pump which came after the STFT's started showing..)
Perhaps a calibration period for the fuel trims, but I will log if closed loop or not next time to verify.
Maybe closed loop enables once the LTFT's start moving? (That short log ECT got to 99deg and no LTFT movement yet)

I figure my sensors must be old and lazy (like the owner!), yet still no codes..
Curious how @lspann3525's O2 sensor acts to set a code..

 

[Fless]

Forgot to log if closed loop..
BUT if looking at the maps in tune, a startup coolant temp of 56degF should not activate closed loop until coolant reaches approx 105degF..
View attachment 480163
(And I was at 90-95degF ECT during the brake pedal pump which came after the STFT's started showing..)
Perhaps a calibration period for the fuel trims, but I will log if closed loop or not next time to verify.
Maybe closed loop enables once the LTFT's start moving? (That short log ECT got to 99deg and no LTFT movement yet)

I figure my sensors must be old and lazy (like the owner!), yet still no codes..
Curious how @lspann3525's O2 sensor acts to set a code..

LTFTs won't move quickly, by definition. They are accumulated STFTs and averaged over time.

 

[mikez71]

Another log, cold start ECT 129degF, LTFT start moving 17seconds after startup.
I think it could have moved earlier (10 seconds after startup) but I didn't touch the throttle (lightly) until 15 seconds after startup..

Despite being "long term" it can bump or dip in under 1 second..
Typically moving every few seconds while driving. (But doesn't move at idle)
Changes right along with throttle/MAP consistently...

It seems like smaller changes maybe based on STFT, but larger changes might take something else into consideration, like throttle input..
(STFT goes down, LTFT goes up, doesn't correlate directly, but LTFT matches throttle input)

 

[West 1]

The brake pedal test is a quick way to see if your O2 sensors are reacting as they should. Does not work with the Hydraulic power brakes only the Vacuum power brakes of course.

 

[lspann3525]

I went ahead and ordered a GM upstream o2 sensor from RA to see if that will help.

Searching thru the forum I did find a tsb that effects 2008. If it is a PCM issue anyway for a do-it yourself person to fix it?

https://www.tsbsearch.com/GMC/08-06-04-045A

 

[SpareParts]

I would think for that TSB you should go to the dealer as it does not seem like you are set up to do it.
Do you know and are you capable of doing it?

 

[lspann3525]

Could probably do it if I got my hands on a Tech 2

 

[LsHart]

SWAG: transmission torque converter shudder?

Also when replacing O2 sensors it's best to use OE and do it in pairs.

Injector balance test?

 

[LsHart]

Injector balance test?

I'm late here or has this been tested?

 

[lspann3525]

not yet. Im not sure I can do it with nucar or elm327

 

[mikez71]

There are a few differences

I went ahead and ordered a GM upstream o2 sensor from RA to see if that will help.

Searching thru the forum I did find a tsb that effects 2008. If it is a PCM issue anyway for a do-it yourself person to fix it?

https://www.tsbsearch.com/GMC/08-06-04-045A

I did notice a few differences between '12 and '08 in hptuners, but that doesn't mean that's all the changes, so I would get an update with SPS..
I believe @j91z28d1 has used the OBDxPro? to program if you intend to program it yourself.
Here's a some changes that show up...

'08

just a couple changes in '09, main difference being the Closed loop proportional multiplier vs ect.

'12

 

[mikez71]

Last observations on o2/closed loop.. It's @lspann3525's fault!

Cold start, 55degF ECT, LTFT dips 13 seconds in, after releasing brake.
Truck has been driving a few seconds, STFT no movement yet.
18 seconds in (cursor line) STFT moves and it is in closed loop, behaving as @Fless said, although my old sensors haven't warmed up yet.

Same cold start 'fuel trim learn' not active until 3min2sec after startup.
LTFT oscillating about every 3-5 seconds as truck is crawling around the lot in 1st gear.
More frequent than my light braking, and not really lining up with braking.

Warm restart ECT 122degF, o2's still warming up?
STFT starts moving and closed loop activates 10seconds after startup (cursor line).
Fuel trim learn active 1.7 seconds after closed loop activated.
LTFT no early movement (no braking/MAP change or driving yet),

 

[Sly1]

Typically this code is caused by a faulty O2 sensor. I have had the same code when a catalytic converter started clogging and getting restrictive. That one was a fun one to figure out.

 

[lspann3525]

The GM O2 sensor arrived last week but I havnt installed it yet. My engine light has been off for almost 2 weeks still running the Duralast. Ended up installing a Duralast coil because I started getting a misfire code on cylinder 6.

Since replacing the o2 sensor my truck likes to rev and doesnt bog down will going up hills