New GP Owner

Hi
My name is Steve, I have been a tech for over 30 years (Business systems), and am the new owner of a not so new 2004 Grand Prix GT.

I have had a few issues and managed to fix most of them, however one rabbit I can not trap is the darn P0171. No other DTC's Vacuum tests no leaks, seafoam in last tank, the thing is it comes and goes. I can delete it, and run for a few days then it comes back. Recently replaced the gasket set under the intake P, new MAF, new gas filter, and she has only 155K KMs. Runs like a champ, but this dern check engine light is starting to look like a target... I Have read your forums and enjoy all the input. I hope to be able to input some of my experiences with you all over time.

Cheers

Oilcan

Originally Posted by Oilcan

Hi
My name is Steve, I have been a tech for over 30 years (Business systems), and am the new owner of a not so new 2004 Grand Prix GT.

I have had a few issues and managed to fix most of them, however one rabbit I can not trap is the darn P0171. No other DTC's Vacuum tests no leaks, seafoam in last tank, the thing is it comes and goes. I can delete it, and run for a few days then it comes back. Recently replaced the gasket set under the intake P, new MAF, new gas filter, and she has only 155K KMs. Runs like a champ, but this dern check engine light is starting to look like a target... I Have read your forums and enjoy all the input. I hope to be able to input some of my experiences with you all over time.

Cheers

Oilcan

From the service manual, in order...

1) DTCs other than P0171?
2) Long term fuel trim parameter around 16.4%?
3) O2 Sensor 1 and 2 for correct voltage (200-800mV)?
4) Vacuum hoses for pinching, kinks and proper connection?
5) Alcohol in fuel?
6) Check O2 sensor wiring and connectors?
7) Short between O2 sensor signal and ground?
8) Vacuum leaks? Induction leaks? Canister purge lines plugged? Injector solenoid coil test? PCV leaks?

I hope this points you in the correct direction.

Welcome!

Originally Posted by douger

From the service manual, in order...

1) DTCs other than P0171?
2) Long term fuel trim parameter around 16.4%?
3) O2 Sensor 1 and 2 for correct voltage (200-800mV)?
4) Vacuum hoses for pinching, kinks and proper connection?
5) Alcohol in fuel?
6) Check O2 sensor wiring and connectors?
7) Short between O2 sensor signal and ground?
8) Vacuum leaks? Induction leaks? Canister purge lines plugged? Injector solenoid coil test? PCV leaks?

I hope this points you in the correct direction.

Thank You... I'm on it.