Hey guys I've been trying to troubleshoot this problem since March. Car is a 2001 Pontiac Grand Prix GTP with only 71,000 miles.
Here's the problem, back in March one random day while I was driving my engine started studdering and finally stalled while I was giving it gas. It re-started with no problems.
The next day, while driving on the highway, it did this 3 times in 20 minutes, all while cruising at 70mph. Each time, I pull over, turn the car off and back on. Then on the way home it didn't do anything.
I had the crank position sensor replaced. The plugs look fine. Cleaned the MAF with CRC. It's still doing it. Next step will be to unplug the MAF to put it into speed density mode.
Here's what I DO know.
-Car restarts fine everytime
-Totally random, can't reproduce it.
-If Im driving and it starts to studder, the engine will remain stable as long as I don't give it more than ~10% throttle.
-After it starts to studder, when I give it more than ~10% throttle, the engine will stumble worse and then stall. When I give it more than ~10% throttle, my Scanmaster says .000 millivolts for the O2 sensor. I'm 95% sure thats why it stumbles and stalls.
Today 6/26/2009 on the way to work it stalled SIX times within a 3 mile distance. Each time it restarted with no hesitation.
