G8 Procharged throwing P0171, P0174, and P0556

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I got my car dyno tuned, results: 436rwhp/403ft-lb @ ~9psi.

Spec's:
D1SC procharger
3 core intercooler
FAST 57lb/hr @58psi fuel injectors

Now to the issue(s): After driving the car for a while i started feeling the brake different, whenever i approached to a light and applied the brakes, the pedal started vibrating. Then few minutes after i got the check engine light with the following codes:

P0171--Fuel Trim Lean Bank1
P0174--Fuel Trim Lean Bank2
P0556--Brake Booster Pressure Sensor Circuit Performance


Now to the facts, i know that P0556 code is due to a vacuum leak and the other two most people here associate them also to a vacuum leak. I've been trying to trace this down but i seem to get nowhere. I took all the vacuum hoses out and check for cracks, none, I tied all the hoses with zip ties and reset the codes. The brake pedal still feels weird and I'm still getting the codes. The only things i have not check are two check valve: one that is attached to the hose that goes from the front of the intake manifold (behind the throttle body) and the one attached to the brake booster. NOTE: Procharger makes you attach a vacuum block in from the back of the intake manifold to the check valve attached to the brake booster (this is done by cutting 3 1/2'' segment of the main brake booster vacuum hose and attaching the vacuum block) for the surge valve to get vacuum. In my opinion one can attach the vacuum block somewhere else in the manifold, perhaps from the front of the intake manifold.

I attached two log files so you guys can disseminate anything if possible...

I setup the new injector flow rate myself by just adding 1.3 to the IAT multiplier table. When i got to the dyno i had the P0174 code. My STFT were messed so the tuner adjusted all fuel trims. He setup the AFR about 11.5@5k rpm


Any help or feedback will be appreciated, thanks in advance,
ALEX

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No feedback??

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Help help please!!

[goober]

Your check valves might be leaking. Check those. I dont think this is a tune problem but a mechanical problem.

[GMRACIN]

I typically do NOT tap into vacuum going to brake booster

[pdsq98gt]

Sounds like your brake booster isn't getting the vacuum it needs. Is the vacuum line connected from the booster to the intake manifold?

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Thanks for all the feedbacks.

Yes the vacuum line is connected from the brake booster to the intake manifold. Procharhger makes you tap into that line to attach a boost gauge and feed the surge valve.

[pdsq98gt]

I would hook up a vacuum pump to the booster and make sure it holds vacuum. Or plug the booster hose and see if the lean condition goes away.

[[email protected]]

It turned out that the intake manifold was leaking, re-torqued it, problem solved.

[pdsq98gt]

Must have been a pretty bad leak to not allow the brakes to work propperly.

[goober]

I knew it sounded like a mechanical problem and not a tune problem. Glad you got it fixed.

[REDNECKRACING]

P0171 And P0174 Will Be A Vac Leak After The Maf Sensor. If There Are No Vac Leaks Then It Is An Intake Leak.

[MyLS1Hauls]

P0171 And P0174 Will Be A Vac Leak After The Maf Sensor. If There Are No Vac Leaks Then It Is An Intake Leak.

Or improperly scaled IFR tables/offset tables.

[SMG Motoring Inc.]

Good to see the prob solved...as mentioned above i would be a little uncomfortable with my vacuum booster NOT getting full vacuum from the source, i would stay away from t-ing off etc. Knowing that wasnt the problem thats a good thing... but just thought id offer my .02 about it.

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Update. Unfortunately I'm still getting the P0556 code and I'm still haven't been able to figure out this.

[DrLoch]

The vibrating in the pedal you were feeling is the ABS unit trying to help generate brake pressure which then generates the code. I suggest that you put a vacuum gage in the line running to the booster to see if you generate any vacuum at all.

Can you see the booster sensor? Is it on the booster or between one of the check valves and intake manifold.

I would also take would also remove anything else from the booster vacumm line until you get this figured out, it one thing to go fast, quite another to stop.

[[email protected]]

Thanks for the feedback,

I suggest that you put a vacuum gage in the line running to the booster to see if you generate any vacuum at all.

I will try that tomorrow.

Can you see the booster sensor? Is it on the booster or between one of the check valves and intake manifold.

Yes, it's located below the brake master cylinder and attached to the brake booster.

Right now i don't have anything attached to the vacuum line, i put a brand new OEM brake booster vacuum hose.