Codes p0172 and p0175, fuel problem?

Hi,

Are the fuel trims still the same? As far as a neg 34 STFT, that indicates the PCM is trying to cut the amount of fuel to the cylinders. Often, that is a result of a faulty fuel pressure regulator. Have you checked if the pressure is within the manufacturer's specifications? If not, that is where I would start.

Here is a link that explains in general how to check it:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

I attached the manufacturer's fuel pressure specifications below.

Let me know what you find or if you have other questions.

Take care,

Joe

See pic below.

Just checked it and it is in spec. what is the next you would try and yes they are still negative?

Hi,

The next thing to check is how quickly the fuel pressure drops off when you turn the key off. There could be an injector issue (leaking). Also, make sure there are no air restrictions between the air filter and throttle body.

Let me know.

Joe

Fuel is good and no leaking.

Hi,

I went back through the pics you attached above. I didn't notice any for the engine coolant temperature sensor. Before starting the vehicle, what signal is the ECT sending to the PCM?

Let me know.

Joe

ECT is reading valid outside temperature I thought it could be IAC Valve so change throttle body same problem could the intake runner make it run rich on both banks. When I was cleaning intake, I took the runner off.

Hi,

Anything is possible. A failed runner can cause air/fuel mixture issues. The runners are actuated under full throttle, so it could be related.

Have you had a chance to inspect them?

Let me know.

Joe

It was mds system.

Hi,

I'm not a fan of the MDS system. Were you able to resolve the issue?

Joe

Yes

Hi,

That's good news. I'm glad to know you found the issue and were able to resolve it.

Take care of yourself and feel free to come back anytime in the future.

Joe