I could use some help please

[dtek]

My car has been having it rough lately. Yesterday someone backed into my driver side door while I was parked, and I’ve been having engine trouble. I have a 2012 3.6L v6 LFX (1lt) Automatic trans.

HERES A VIDEO OF MY AIR:FUEL while in idle: https://youtu.be/NM0G9XtOTQ8


Symptoms:
1) ECM P0171 - System too lean (bank 1)
2) ECM P0174 - System too lean (Bank 2)
3) ECM P0191 - Fuel Rail Pressure Sensor giving inconsistent readings.
4) Service Stabilitrak will flash on for about 5 seconds then go away.
5)Randomly goes into limp mode.
6)Fuel Rail Pressure (after air is bled out, and with engine on) reads about 55psi.

What I’ve done already trying to fix it:
1) Checked for vacuum leaks.
2) Replaced PCV hoses/connections.
3) Replaced CAI filter.
4) Replaced CAI fittings/connections.
5) Replaced Mass Air Flow sensor.
6) Replaced Intake Manifold gasket.

My Car Has:
1) 115k miles.
2) 5w50 Mobil 1 oil.
3) Autolite AP5263 colder spark plugs.
4) Spectre CAI.
5) K&N RF-1041 CAI filter.
6) Gasket matched, ported intake manifold.
7) Phastek Air Scoop in front bumper grille.
8) Catless downpipes.
9) Magnaflow Resonated X-Pipe.
10) 2x Jones Full Boar Racing mufflers.
11) Resonator delete.
12) 2.5” pipe to 4” tips
13) 2.5” pipe through the whole exhaust.
14) OverKill 93 Octane Tune (TCM tune aswell)

[KillboyPowerhead]

I'm no expert, but...

Anyway to test the fuel pump?

If the pump is good, maybe a professional (high-pressure) cleaning of the fuel lines and injectors.

[Greenhornet2]

watch the fuel pressure as you drive, under load high rpm maybe your fuel pressure is dropping off. or your fps is reading erratically. Sounds like a fueling issue

[dtek]

Originally Posted by KillboyPowerhead

I'm no expert, but...



Anyway to test the fuel pump?



If the pump is good, maybe a professional (high-pressure) cleaning of the fuel lines and injectors.

I just put some of the High mileage fuel injector cleaner fuel treatment stuff in, still having the problems. Seems to be more frequent now.
And as for testing the fuel pump, no way seems easy due to the location of it and having to cut a hole in your trunk to access it

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[dtek]

Originally Posted by Greenhornet2

watch the fuel pressure as you drive, under load high rpm maybe your fuel pressure is dropping off. or your fps is reading erratically. Sounds like a fueling issue

The Autocal hand tuner that I’m using to view the data as I’m driving doesn’t show me fuel pressure, but it does show me the fuel trims. The fuel trims are insanely high, adding about 35-45% more fuel


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[Greenhornet2]

Can you read your oxygen sensor voltages? If there are no vacuum leaks then I would be looking at the O2S slow moving or stuck. If they are stuck reading lean the ecm will try and add fuel. Adding that much fuel you would be running very rich, unless there is truly a vacuum leak.

[CamaroBarb]

The fuel system in your car is complicated. I would recommend having a pro at least diagnose it. It could be as simple as changing out the pressure sensor. If you want to throw parts at it that maybe the 1st thing to try. I would check the o2s like mentioned above. Looks like from here the fuel pressure controller is failing or not seeing proper readings from the fuel pressure sender causing low fuel fuel pressure. You could check the connections at the fuel pressure controller, its mounted behind the pass side rear seat panel. Could also have a dirty fuel filter but its not serviceable on these cars as far as I know, I'd try a bottle of Thechron with only 5 gals of fuel so its strong, it may be enough to clean it out if that's the trouble.

[TommyTheCat]

Definitely sounds like a fuel pressure problem. You can still check the low pressure fuel pump to make it's not a problem, but more than likely the high pressure pump is going out.

[Greenhornet2]

I always forget these are direct injection engines, I don't have experience with them first hand.

[wasthatacop?]

Originally Posted by Greenhornet2

watch the fuel pressure as you drive, under load high rpm maybe your fuel pressure is dropping off. or your fps is reading erratically. Sounds like a fueling issue

I agree. Sounds like a fuel delivery issue... fuel filter, fuel pump, injectors.

[CamaroBarb]

I was having some off symptoms, the throttle would just feel flat above 1/4 throttle most of the time. I put some Lucas fuel treatment and a bottle of Techron in the tank. Seemed to solve the issue so far. I'm sure my car was used as a salesman car before I bought it and most likely used gas from a company pump. The reason I say this is the filler opening was nasty dirty and so was the inside of the filler pipe. Like it was filled around dirty conditions every time.

Lisa Kudrow looks like she has a dinosaur's head.

[dtek]

Originally Posted by TommyTheCat

Definitely sounds like a fuel pressure problem. You can still check the low pressure fuel pump to make it's not a problem, but more than likely the high pressure pump is going out.

How would I go about testing both the pumps? I went to my local auto shop last night and they hooked up some gauges to the nipple behind the intake manifold and that reading was:


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[dtek]

Originally Posted by CamaroBarb

I was having some off symptoms, the throttle would just feel flat above 1/4 throttle most of the time. I put some Lucas fuel treatment and a bottle of Techron in the tank. Seemed to solve the issue so far. I'm sure my car was used as a salesman car before I bought it and most likely used gas from a company pump. The reason I say this is the filler opening was nasty dirty and so was the inside of the filler pipe. Like it was filled around dirty conditions every time.

Lisa Kudrow looks like she has a dinosaur's head.

I’ve tried those fuel treatment things before, I’ll try them again though


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[dtek]

Originally Posted by wasthatacop?

I agree. Sounds like a fuel delivery issue... fuel filter, fuel pump, injectors.

Is there a way to narrow it down to which one of these things it is?