Help! P219b

[Tankster696]

Help! 2015 GMC Yukon xl with the dreaded p219b code. I've replaced coils,wires,plugs, injectors,maf,and both 02 sensors. I've used all ac Delco parts. No vaccum leaks. I'm completely stumped. Any suggestions please and thank you kindly

 

[Fless]

Welcome to TYF!

I hope that your source for AC Delco parts is solid; we've seen a lot of fake OE-branded parts in the market.

I'd be curious what the short- and long-term fuel trims are, both at idle and about 1,800 rpm.

This from www.charm.li for an earlier model year:

* The fuel trim cylinder balance diagnostic is very sensitive to heated oxygen sensor (HO2S) design. A non-OE sensor or an incorrect part number may cause a DTC to set.

* Monitoring the misfire current counters, or misfire graph, may help to isolate the cylinder that is causing the condition.

* Certain aftermarket air filters may cause a DTC to set.

* Certain aftermarket air induction systems or modifications to the air induction system may cause a DTC to set.

* Certain aftermarket exhaust system components may cause a DTC to set.

 

[OR VietVet]

Welcome to the forum from Oregon.

I see you have the code P219B but you stated no symptoms. It is stating the problems appears on the Bank 2 side. Maybe it was time for all the parts you threw at it that addresses both sides. What @Fless said about the short and long term fuel trims is spot on. I would bet, since you replaced all those parts, with hopefully rock solid ACD parts, that it sounds like a vacuum leak. Did you check for that possibility? Did you have any recent work done? Need to attach a Live Data scanner and figure this out.

 

[Tankster696]

At idle short fuel trim fluctuate between -0.8 to 1.6 long fuel trim stays -3.9 at idle. At 1800 rpm sft fluctuate between lowest -5.5 to 1.6 and lft stays at -1.6

 

[Tankster696]

On the bank 2 side the short fuel trim fluctuate from -0.8 to 0.8 and long fuel trim is -14.8 at idle and at 1800 rpm sft -0.8 to 5.5 and lft -20.3

 

[89Suburban]

At idle short fuel trim fluctuate between -0.8 to 1.6 long fuel trim stays -3.9 at idle. At 1800 rpm sft fluctuate between lowest -5.5 to 1.6 and lft stays at -1.6

You remind me of SVG bro.

 

[Tankster696]

SVG? I'm sorry I'm new to the forum. Don't know what that is.

 

[Tankster696]

Welcome to the forum from Oregon.

I see you have the code P219B but you stated no symptoms. It is stating the problems appears on the Bank 2 side. Maybe it was time for all the parts you threw at it that addresses both sides. What @Fless said about the short and long term fuel trims is spot on. I would bet, since you replaced all those parts, with hopefully rock solid ACD parts, that it sounds like a vacuum leak. Did you check for that possibility? Did you have any recent work done? Need to attach a Live Data scanner and figure this out.

I have not had any recent work done at all except I changed the 02 sensors myself with acd. I did attach a live scanner and those were the results I posted for the fuel trim. I did also notice the low pressure pump was about 45 psi and fluctuated and under load I did see it drop down to 37 psi a few times. And the Hpfp is running around 580 psi if that helps any.

 

[swathdiver]

Help! 2015 GMC Yukon xl with the dreaded p219b code. I've replaced coils,wires,plugs, injectors,maf,and both 02 sensors. I've used all ac Delco parts. No vaccum leaks. I'm completely stumped. Any suggestions please and thank you kindly

This code was prior to all those parts being replaced, yes?

Did you double check that the oxygen sensors were screwed down all the way? I did this once and it threw that code.

Any other DTCs (codes)?

If you can see live data, is your MAP reading at idle between 19-42 kPa?

The shop manual for the previous generation engine says this about that code:

and

 

[Tankster696]

The code was prior yes. That's why I kinda went fishing and started replacing everything that was related to that code or so I thought. Map is running at 4.1 psi at idle.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

 

[swathdiver]

The code was prior yes. That's why I kinda went fishing and started replacing everything that was related to that code or so I thought. Map is running at 4.1 psi at idle.

If yours were mine I'd spend the $20 to get access to the troubleshooting guide at AllDataDIY. I would be wanting to check the injectors and your mention of that low pressure pump varying that much piqued my interest. On my older truck, the pressure basically only has two settings and doesn't move more than 2 psi and if it does, the pumps are usually bad. But I'm no LT engine expert.

 

[jaxscuby]

short fuel trims (SFT) the ecu adjusting air mixture to try achieve afr 14.7:1 at idle
so for the range of -0.8 to 1.6, percent adjustment within limits.

On the bank 2 side the short fuel trim fluctuates from -0.8 to 0.8 and long fuel trim is -14.8 at idle and at 1800 rpm sft -0.8 to 5.5 and lft -20.3

short fuel term -0.8 to 0.8, good
@1800 short fuel term -0.8, good, & long fuel trim of -20.3, running abit rich...

what does your air cleaner look like? abit too much fuel and not enough air.

could be a "sticking" injector..take out & inspect/clean..

usual trouble shooting..inspect air filter, maf, hoses/clamps, O2.

fuel trims are a by product of the ecu seeing the air that goes by the maf and then ignited, and out past the front O2.

So why is it taking away 20%, running rich on that bank.

when i was tuning turbo rice burners, I would explained abit rich is alot safer than abit lean..

also I would log maf sensor for grams per sec vs voltage with STF & LTF to see how much fuel the ecu was
either taking away or adding due to the combination of parts...

then adjust values in the maf table..FYI the graph of the maf table "supposed to" look like an exponential curve.

now exponential curves have "orders", how quickly the curve goes from almost flat to near vertical.