Car stalling and P0171

[Codester]

I've been having this issue for a couple months. I thought the P0171 and coolant loss was from my LIM. Well I replaced the gasket and UIM but it still has this P0171 code.
Sometimes on acceleration it jerks like it cut off fuel for a second and sometimes while going through a turn at the light that requires to let go of the gas or sometimes at the lights it just stalls out. I turn it back on but I have to give it gas for a bit to prevent it from stalling again.

The SES light for P0171 usually comes on after these events. MAF or vac leak? I cleaned the MAF while doing the LIM fix with electronic parts cleaner.

 

[burgundybullet]

Check for a vac leak. About a month ago my car was throwing that code and a MAF circut low input code I think and I just needed a new MAF. Since it doesn't say anything about low input and the P0171 is a Bank 1 lean code I think it could vary well be a leak.

 

[Codester]

That's what I was thinking but it's so an intermediate issue. It idles fine most of the time and not high. And the SES light turns on and off

 

[burgundybullet]

I think someone told me that an O2 sensor on the fritz may cause that code to be thrown too. May want to check into that as well if you can't find a vac leak anywhere.

 

[Codester]

Usually an o2 sensor isn't the problem with a p0171 as from what I read from Bill on this forum

 

[burgundybullet]

Go with what Bill said. He knows everything. haha. He knows his stuff when it comes to 3800s.

 

[blueguy]

Running to lean trips the vac leak code.

You can easily test it by spraying carb cleaner around the engine bay while the car is idling and when the revs jump up you've found the leak.

I'd also try unplugging the MAF and starting it to see if that helps.

 

[Codester]

Yep been trying to find a vac leak like that. It's the same as finding a boost leak in a way. I've had 4 turbo DSMs lol. I think it might be my EGR pipe. 180k on this motor.

 

[Codester]

Well sprayed everything I could with carb cleaner. Nothing. I'll do it again with the engine warm as that is when it stalls. I think I hear a hissing sound from the plastic fitting that connects the brake booster hose to the UIM. I have a new Dorman UIM. I didn't RTV that o-ring. Should I of did that while installing? I sprayed it and nothing. I'm thinking its the EGR tube.