Possible MAF problem on 99 Grand Prix ?

Asked by May 02, 2009 at 10:54 PM about the 1999 Pontiac Grand Prix 2 Dr GT Coupe

Question type: Maintenance & Repair

My 1999 GT died suddenly last week while driving, i could start if but it would died immediately, unless i kept the RPM's up,but it would run rough and run very rich.
I had it towed to the shop and it ended up starting up and run fine, no codes so they couldnt diagnos anything. I drive it about 20 miles and it died again with the same restart issues.
I decided to tow it home to work on it myself. Same thing, starts and runs at times, other times starts and dies immediately unless i keep the RPM's up. It will run but run very rough and and very rich.

I had the Crankshaft sensor replaced about a month ago and ran fine until now.
Could it be the MAF sensor ?

2 Answers


no it would set a code if it was, u sure its running rich and how rough could be spark plugs if they are cracked slightly it may only run like that when u get the car warm and that would explain the rich running bc there will be unburnt gas, also could be one of the 3 coils try to get a good clear video of what its doing. im ASE certified so im not gonna give u a bunch of bs answers i went to lincoln tech grad with a 3.5 neways get the video and check the engine temp


There is a part under the front passengers side fender above the wheel well Called a fuel pump resistor. If that goes bad as it did with me you can Keep the car running if the rpms are kept high. Just go to the nearest Parts store ask for a fuel pump resistor. It's a circle or oval ceramic resistor With a plug coming out of one side. But that is the problem. Don't mess Around screwing with all the made up stuff from twenty thousand certified Mechanics. I have the exact same car and it did the exact same thing And that particular part was the only electrical sensor I had NOT replaced Good luck man

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