1999 GTP supercharged setting maf codes, tp sensor and others

[Maxx1212mx]

Hey everyone I am new to the forum. I am having trouble with my grand prix gtp i just bought. It is a 99' GTP 3.8L supercharged. I have been working on cars a while so im not clueless but I am stumped. The car keeps setting MAF codes along with TP sensor codes. Both sensors have been replaced. The car will die intermittently after about 35 min of driving. If I pull over and clear the codes the car will run fine for a little bit or as long as a few days. I have performed throttle body clean. I just replaced battery. When I unplug the maf it runs worse sometimes and not other times. same with the tps its very inconsistant. I have also had a cat effiency code and a trans pressure solenoid code but i cleared that initally when i bought the car and hasnt came back yet. I am thinking maybe PCM or MAp sensor. I dont have tech2 available. PLEASE HELP also its seems sometimes when i am driving down the highway it will feel as though something engages and takes power away. the rans will shift way too firmly and if i come to a stop i will have to double foot the pedals or it will die

[chrissbee77]

im not sure if this will help but my car was doing the same thing and it turned out that the (BTMI) fuse was blown. just a thought. good luck

[BNaylor]

It sounds like you have multiple issues. With the CAT converter code assuming it is P0420 DTC it sounds like the converter is one issue.

The shifting is abnormal due to a pressure control solenoid (PCS) issue. Code P1811?


And welcome to AF.

[transkiller]

I am currently stumped by this exact same problem did you ever figure out what happened

[richtazz]

Welcome to AF MAXX and transkiller

Do either of you guys have the actual PXXXX codes stored? If so please post as it will greatly assist us in helping you.

I agree with Bnaylor that you may have a cat issue Maxx. Being a just purchased GTP and many get modded by previous owners, is it possible the car has a hi-flow or cheap aftermarket cat on it? Many of these will trip cat codes due to not being up to factory specs.

On the MAF issue, what brand replacement MAF did you buy? If it's a Cardone brand, there is a good chance your new one is junk. When you unplugged it, did you do it with the car running or off? You don't want to unplug the MAF while it is running. Unplug it with the car off, then start it and give it time to adjust. If it runs better then, the replacement MAF is suspect.

[transkiller]

I am having a p0101 i believe for the maf and i don't remember the tps code i think it wasa p0122 both were for the sensor out of range. i used bwd parts to replace the tps, maf, and iac ( i had a code for the iac but only once it never came back). i've also replaced the plug wired and plugs and still nothing. the car idles at 2k and when i hit the gas it spudders, but it started just stalling randomly and progressed. now the car is undrivable and i'm stumped any help would be greatly appreciated!!!

[richtazz]

Transkiller,

p0101 is MAF out of range
p0122 is TPS low input circuit

These could be a wiring harness or connector issue (but not as likely as a bad component), as both are at or near the throttle body. Codes were cleared with a scan tool after new parts were installed, correct?

Also, have you done a fuel pressure check? Borderline/low fuel pressure will exhibit these symptoms as well and cause codes to pop up even though the sensors are fine due to how the PCM tests certain components.

[transkiller]

i'm going to be renting a fuel pressure tester to make sure i have good fuel pressure, but i'm leaning more towards and electrical problem only because it all started when my boost gauge stopped working.