check engine light. code P0171

[BNaylor]

How is your fuel pressure? Abnormal fuel pressure can set the DTC. The DTC can be caused by leaky supercharger or lower intake manifold gaskets. Basically, a manifold vacuum leak. You can use starter fluid spray or propane to some extent for leak detection. Check where the supercharger mates to the lower intake manifold and where the LIM mates to the cylinder heads. And then each fuel injector where they insert into the cylinder heads looking for possible bad lower fuel injector o-rings. Also, where the throttle body mates to the supercharger. I would not use carb spray cleaner because it may damage the rubber and plastic parts and wiring. Look for changes in idle. Did you have the mechanic run an engine vacuum test?

[TDWPgtp]

we didnt do a vac test but we could. hes my friend and we were doin as much as we can without using the shop he works at cuz they charge him to use it. but if we cant find any other causes we may have to try that.

[Mickey#1]

Were those long term & short term fuel trims taken at idle? Can you get another scan at both idle & again with the boost around 0?

[BNaylor]

Best thing to do is the easy stuff or external it rule it out before going internal to the engine. On engine vacuum you can tap into the MAP sensor vacuum line or right off the throttle body vacuum lines. Range is 15 - 22 in-hg with a typical 0-30 in-hg automotive vacuum gauge. A good typical reading at idle will be around 17-19 in-hg and then take rpms to 2000 where the reading will probably be higher once it stabilizes.

Didn't you have an issue with overheating? These two issues could be related and I would suspect the supercharger and LIM gaskets especially if they are the original or never been replaced. Upon tear down and further inspection you will see they will not be in too good of shape considering you have a '97 GTP and based on your mileage. Mine looked terrible when I replaced them a few years ago when I upgraded to a S ported M90 supercharger.

[TDWPgtp]

well i just had it scanned again and got more codes... i know the P0171 is lean fuel and P0118 is that the coolant sensor is sensing wrong basically, and i dont really know about the P0102. for the 0118 and 0102 codes i could use some help if anyone knows anything about them or any possible remedies itd be great. thanks

[BNaylor]

Originally Posted by TDWPgtp

well i just had it scanned again and got more codes... i know the P0171 is lean fuel and P0118 is that the coolant sensor is sensing wrong basically, and i dont really know about the P0102. for the 0118 and 0102 codes i could use some help if anyone knows anything about them or any possible remedies itd be great. thanks

TDWPgtp,

Your latest post has been merged with the existing post you had which appears to evolve around the same issue(s). Try to keep these issues together so it cuts down on confusion, duplication or redundant answers.

The P0118 DTC is related to the ECT (engine coolant temperature) sensor. A high input. The P0102 DTC is a MAF sensor issue. The PCM module has detected a low frequency input from the MAF sensor of less than 1500 Hz.

[TDWPgtp]

im sorry i thought it was an unrelated problem and that the code just hadnt been reset. but im assuming it is because of this because i had the code cleared and it did come back again. they supposedly cleaned the injecters and replaced the upper and lower manifold gaskets as well as the super charger gasket. no vac leak has been found and i would assume that they checked the MAF but im not sure as of now i didnt get to talk to the guy yet. ill be stopping by either tomorow or wednesday and will post here with more info
thanks

[mortkb]

Check for vacuum leak. The tube from my intake boot to the intake manifold was off. Car runs smoother and P0171 went away.

[Tech II]

Four year old post.....hope TDWPgtp sees this....