Random P219A (Fuel Trim Cylinder Balance Bank 1)

[Fless]

Just goes to show that even if a part is made by an OEM (Original Equipment Manufacturer) it may not be the same as Original Equipment. No guarantees unless you're buying OE. Watch those initialisms when you buy.

 

[Charlie207]

well so I thought this p219A was solved but apparently not. It reared its ugly head again!!!!! Would my AirAid Modular Intake Tube, #200-996 course this issue? The reason I ask is that the GM service manual states to inspect the air induction system for modified damage leaking or restricted components and the AirAid MIT is a modification.

When do you notice the CEL come back? I only get it when I've romped it to redline, but it's sporadic, and not always after working the engine hard.

 

[opfor2]

When do you notice the CEL come back? I only get it when I've romped it to redline, but it's sporadic, and not always after working the engine hard.

I usually get it when I leave work I have a 132 mile round trip home and in the early hours I average 70 mph going home it’s usually anywhere from 65 to stop and go traffic. But the CEL will come on the first 20 min of the drive home then turn off two to three days of driving around town

 

[opfor2]

So every now and then I get a random p219a code. It will set and then a day or two later it will clear and then show up again a week or so later. I looked at all of the suspects per (https://charm.li/Chevrolet/2011/Suburban 4WD V8-5.3L/Repair and Diagnosis/A L L Diagnostic Trouble Codes ( DTC )/Testing and Inspection/P Code Charts/P219A/) and all seems well. I'm at a loss as to what else to try any ideas would be helpful.

UPDATE 2: yesterday I replaced the "aftermarket" Denso O2 sensors with OEM GM O2 sensors also made by Denso. First photo shows the new GM O2 sensor, second photo shows the removed "Aftermarket" sensor and the third photo shows both side by side new on the left and old on the right. I hope this fixes my P219a DTC

***Final Update*** So, as I mentioned in update #2, I replaced the aftermarket Denso 234-4668, "Upstream" O2 sensors with "Genuine GM #12583804 O2 sensors and for the past month I have not had the P219A code show up. As stated in the attachment in post#18, apparently my Tahoe is sensitive to non-OEM O2 sensors. Hope this helps someone in the future.

 

[DaveO9]

Could P219A be caused by an DS exhaust manifold leak? I had this code show up a year ago on a 1500 mile road trip to CA to pick up my daughter from college. That time the light came on a few hundred miles into the trip and then went out on its own several hundred miles later. Stayed off for good then, and didn't come back for a year. Same trip just a few weeks ago, light comes on again, same code. Now it seems to be here for real. I reset it with my tech 2, stayed off around town for a week, but then on another road trip, it came back on.

But now I'm noticing what I'm fairly certain is an exhaust leak from driver's side, through the wheel well, on cold starts. I can hear it for a minute or so, then it's not audible. I know the back bolt is broken on DS manifold. Seems like this, albeit small, leak that is pre-O2 sensor could cause an imbalance reading? I've ordered the Dorman clamp for that manifold. I think I should try and clean up that leak, even if it is not causing the code.

Here's my original thread from a year ago. https://www.tahoeyukonforum.com/threads/on-road-trip-getting-p219a-code.148867/

 

[DaveO9]

Dorman clamp came overnight, so I installed it today. I thought I’d knock it out in a couple hours since I installed one on my ‘09 Tahoe a couple years ago, but nope - all afternoon. And a lot of scraped skin on elbows forearms and knuckles. But got it on, and no more audible exhaust leak. Cleared the code. I have another short road trip pulling my Tavel trailer tomorrow - will see if CEL stays off.

 

[DaveO9]

Well the Dorman clamp worked as intended, no more exhaust leak, but the P219a code came back after 100 miles or so of driving on the road trip this weekend. Time to move on to looking for vacuum leaks in the PCV and evap hoses. In my thread from a year ago that I linked to above, I was wondering if it was due to a catch can I installed right before that trip. Suggestion then was to bypass it. I never did that because the code went away, but now I will try that first. I also have a non-stock air intake, so I'll be looking at that, possibly going back to stock for trouble-shooting.

 

[DaveO9]

Well now the CEL is off. Just a few in-town drives after the weekend's road trip and it went off on it's own. Last night I noticed I didn't have a clamp on the PCV intake hose that comes off the main air intake. I installed one there - just maybe I have a slight leak there, but I doubt it. I'm guessing I have a dripping fuel injector or an O2 that's going bad.

 

[DaveO9]

Just a quick follow up on this issue: no CEL since I added the clamp to the PCV intake hose. Fingers crossed that it's resolved. Drove it on vacation to BC last week, 500 miles each way. Previously it was only long trips (100+ miles) that would trigger it.

 

[usdlawstudent]

any updates after this? I’m running into a similar issue with my 2010 Yukon Denali. I replaced all four o2 sensors and was check engine light free for months, but it came back today. Where is the pcv valve on these engines exactly? Is there a pic somewhere? I tried google, but couldn’t find a clear answer.

 

[dkad260]

any updates after this? I’m running into a similar issue with my 2010 Yukon Denali. I replaced all four o2 sensors and was check engine light free for months, but it came back today. Where is the pcv valve on these engines exactly? Is there a pic somewhere? I tried google, but couldn’t find a clear answer.

What code do you have stored? Same as OP?

 

[opfor2]

Did you replace the UPSTREAM O2 sensors with OEM GM or aftermarket? If they are aftermarket go to Rockauto.com and get OEM GM sensors.

 

[donjetman]

my 2010 Yukon Denali. Where is the pcv valve on these engines exactly?

The whole driver side valve cover is the PCV. Here is a TSB technical service bulletin to change the valve cover: https://static.nhtsa.gov/odi/tsbs/2014/MC-10114272-9999.pdf