p1153 even with 2 OEM o2 sensors

[WeekenderNutJob]

2008 Yukon XL Denali, 6.2L AWD - P1153 (Bank 2 Sensor 1) code even after replacing the o2 sensor.

Replaced Sensors: About a year ago I replaced both the upstream and downstream sensors on that side with AC Delco ones of the same part numbers when it had codes, which worked well for about a year. Recently started getting just an upstream sensor error, p1153, so I replaced upstream again with OEM, cleared all codes, and ECM memory reset, however, I get codes again after the drive cycle. At this point, I am not convinced it's a sensor issue anymore as the OBD Reader shows that the sensor voltage is working similarly to Bank 1 sensor 1.

Smoke Test: The next assumption was an exhaust or vacuum leak, so I smoke-tested the exhaust from the front intake and from the back exhaust for a potential manifold or vacuum leak, but I did not find anything indicating a leak anywhere on a cold engine.

TSBs: As a side note there is a TSB (https://www.tsbsearch.com/GMC/08-06-04-045A) that talks about the need to reprogram ECU due to gas sulfur levels but I assume if it was an issue with the sensor and ECU reprogramming after an o2 sensor, then it would have been an issue when I replaced the upstream originally a year ago. I always run 91+ octane gas, from top-tier stations, per the manual.

Before I take it to the dealer, for more diagnostics, or ECU reprogramming, does anyone have further suggestions on tests I can do?

 

[WeekenderNutJob]

Hoping to bump this for any feedback. Still not able to isolate the issue. Here is what I have done more since the last post:

Connections: All clean and good.
Fuel pressure: About 60-65 psi key on but not running, and 42 when running which seemed somewhat low...but within the low range of "normal". Fuel pressure is maintained when the key is off and after 5 min.
Injector cleaner: I also am running some injector cleaner through it in case maybe it's a clogged injector on just that passenger side.
Coolant: No use of coolant to suggest a contaminated exhaust.
MAP Sensor: Cleaned recently.

 

[Fless]

Is the fuel system management going into closed loop and staying there?

I would be curious about the short- and long-term fuel trims (both banks) and what the MAF is reporting at hot idle, if you have access to that info.

 

[j91z28d1]

any chance you have an aftermarket airbox of some sort?

 

[WeekenderNutJob]

Is the fuel system management going into closed loop and staying there?

I would be curious about the short- and long-term fuel trims (both banks) and what the MAF is reporting at hot idle, if you have access to that info

any chance you have an aftermarket airbox of some sort?

Nope, bone stock.

Yes the fuel system management is going into closed loop and staying there. Short term and long term fuel trims are lower on bank 2 versus bank 1...but I don't know why. Should I pull the fuel injectors out and test them one by one? Or at least ohm out? My next test I think was going to be either a stethoscope on each injector, or a back pressure test on the catalytic converters.

 

[Fless]

Would still like to see the MAF reading in g/sec at hot idle, just to be sure it's close to engine displacement. And hearing that the fuel trims are lower on one bank than another doesn't really tell much. Where are they numbers-wise? Do the trims change a lot when raising the RPMs to 1500 or 2k?

The upstream sensors can be swapped side to side to see if the issue follows the move.

You can test the injectors without removing them by doing an injector balance test. You'd need a scanner that would do that, though.

 

[WeekenderNutJob]

Would still like to see the MAF reading in g/sec at hot idle, just to be sure it's close to engine displacement. And hearing that the fuel trims are lower on one bank than another doesn't really tell much. Where are they numbers-wise? Do the trims change a lot when raising the RPMs to 1500 or 2k?

The upstream sensors can be swapped side to side to see if the issue follows the move.

You can test the injectors without removing them by doing an injector balance test. You'd need a scanner that would do that, though.

See attached data. Trims don't change much at 1500 or 2k rpm. Even though the sensors on bank 2 sensor 1 and 2 are either brand new, or replaced last year. I think I'm going to swap out the Upstream sensors this weekend and see if the code follows the sensor. And if that doesn't work I guess I'm going to be buying a better scanner with injector capabilities. Currently just using a cheap Bluetooth OBD scanner and the "car scanner pro" app. But I have had my eye on some Harbor Freight upgraded scanners. Anyone have any good suggestions? Maybe something that can actually tell me what injectors are doing.

Also for this weekend would be pulling all of the spark plugs and doing a compression check on each cylinder. Maybe I have low compression in one of the cylinders on the bank two side. Even though there's no misfire data.

 

[Fless]

The only thing that stands out in the screen shots is the sum of the short- and long-term fuel trims for Bank 1; everything else seems okay. Being that close to 10 deserves a closer look at some point, but is likely not related to the current code on Bank 2. (Bank 1: dirty injector? Verify all the intake bolts are tight to spec?)

If the sensor swap doesn't cause the code to follow, then -- and this is a long shot -- I'd be pulling the top of the underhood fusebox and inspecting and reseating the connectors, watching for pin arcing or other circuit issues. So far this is a head scratcher but I think your data and work will eventually indicate the cause.

 

[j91z28d1]

yeah adding 10% fuel to bank one seems a bit high. usually that's closer to +/-5.

not that that helps you much. but yeah, maybe it doesn't like the split. if you swap sensors be interesting to see what it does.


I believe you can add pids to car scanner app if you can find your injector ms pid. it's usually only bank 1 vs band 2 thing. not all 8. the refresh rate is to slow for that to be much help anyways


torque pro might have it with the add on gm pack. but I don't remember forsure and I believe it's only for non iPhones users. but it would work with the same dongle and you can definitely add any pid you can find for it.

 

[petethepug]

On my 09 I’ve got 4 new ac Delco o2 sensors plus all new injectors, new gaskets on lifter valley, intake and exhaust manifold.

New map is next but haven’t checked into all grounds yet.

 

[WeekenderNutJob]

TL;DR: The issue was the TSB reprogramming (not the O2 sensors). When I replaced the part a year ago, I likely installed "new old stock" that premature failed. The second replacement was maybe "new stock," which the ECU read differently? Maybe they aren't exactly the same? Either that or my car is running worse now for some other reason (old cats, worn injectors?) and that was tripping the code just over the unprogrammed ECU levels? Not sure exactly but at least getting the ECU updated, fixed the issue, not another O2 sensor. I am tempted to put the old (from a month ago) 02 sensor back in, but just assume not to mess with it at this point to prove anything to myself.

Long Version:

• Took the car to the dealership for diagnostics after all my efforts had failed. I was done trying to find the issue.
• They said the new AC Delco sensor I had installed about a month ago was bad, and quoted $330 for parts/labor/diagnostics. I let them do it, figuring if it wasn’t the issue, they’d need to address it again at no extra cost.
• Paid ~$330, drove a drive cycle, and the CEL came back on with the same P1153 code in <50 miles.
• Returned the car the next morning and pointed out (again) the TSB for this issue, and gave a full written list of all my previous repairs or tests that were noted above that were related. I also printed out the TSB and gave it to them as I was concerned they had ignored me on that topic the first time.
• This time, I pushed for the ECU reprogramming at no charge—minimal effort/cost for them. They agreed, reprogrammed the ECU, and.... it worked. After a drive cycle, the car passed emissions (Utah only requires CEL off and readiness checks).

In hindsight:
I could’ve pushed back harder initially when they suggested another 02 sensor, but I think dealerships, or pro mechanics, maybe they just distrust any home mechanics. I got the old, recently replaced, sensor back in the deal, and the ECU reprogrammed for "free". I figured the cost of the diagnostics and sensor install roughly equaled what the ECU reprogramming alone would’ve cost, so it’s a wash, and I keep the old sensor and my pride knowing I didn't have the Tech 2 Scanner tools to diagnose it any further or to reprogram it anyways and I was right the first time, just could not prove it without them doing the work. Took it for a 500-mile trip this weekend, with no issues. They also gave me a $50 service credit, so the next oil change is mostly on them I guess.

 

[swathdiver]

Thanks for the info on this. I figured it had to be something with the ECM, didn't think corrupted software was one of them!

 

[j91z28d1]

anyone have the tsb to read?

was reflash part of the tsb?

 

[mattbta]

anyone have the tsb to read?

was reflash part of the tsb?

first post has a link

 

[j91z28d1]

first post has a link

I. must have scrolled right by it.

wow, 2008 specific. that's pretty wild. good job getting it fixed. I would have never guessed a reflash ecm over sulfur

 

[petethepug]

Wholly Ship! Small refinery exception for allowing greater amounts of sulphur than permitted in gasoline?!?!? Thus triggering a check engine light!!

08-06-04-045A GMC System Technical Service Bulletin

08-06-04-045A GMC System Technical Service Bulletin

www.tsbsearch.com

I’m going to have my ECM reflashed even though this TSB says it’s specific to 08.

Just discovered my long cranks are related to a crank position sensor that never triggered a code for years, until it did.

 

[WeekenderNutJob]

I don’t think the gas here in Utah is 80 ppm sulfur based on the article link found below, and this doesn’t seem to be a “small refinery” issue. The state has made significant efforts to clean up Salt Lake City’s winter air. From the sounds of the TSB, it seems the dealership just adjusted the ECU limits to allow up to 450 ppm sulfur before triggering a code.

This might mean it’ll be much longer before I see Catalytic Converter or P1153 codes again, which is good in some ways. However, the downside is that my car may not be helping the inversion/pollution here in SLC. That said, it’s “legal,” and I only drive about 4K miles per year. I usually fill up at a Sinclair station near my house, so my gas should be well below the old 80 ppm sulfur limit based on the article at the bottom.

Maintenance is as follows:

• Oil: Supertech 5w-30 Full Synthetic High Mileage
• Additives:
  
  • 1/2 quart Lucas Synthetic Heavy-Duty Oil Stabilizer
  • Marvel Mystery Oil (in the last fuel tank before my annual oil change)
• Annual Mileage: ~4-5K miles with annual changes.

​

If my fuel and oil shouldn’t have high sulfur content, doing some online searches it seems like my Catalytic converters may be on their way out, not surprising given the 250K miles. Luckily I guess I just bought some time for now without the CEL turning on again anytime soon. I guess I would much rather pay for the reprogram than get after-market converters even for $1K and then still have to do all the work....​

Four Utah refineries now produce cleaner Tier 3 fuels, and the fifth says it will soon

"Utah has five gasoline refineries north of Salt Lake City that produce most of the gasoline consumed in the state. The two largest, Chevron and Marathon, have been producing and selling Tier 3 gasoline since 2019. The next largest, HF Sinclair, says it has been producing gasoline below Tier 3 (7-8 ppm sulfur) since October 2021."