Thread: Completely Stumped

So I'm completely stumped with the wife's 2000 GTP. When I give it gas it takes off just fine until it hits about 20 mph and 2200 rpm's, then it falls flat on it's face. If I hold it to the floor, it will gain speed and a little more rpm till it hits 3000 rpm but so slow that I hardly notice it. I am however able to hold the throttle at a position around 2000 rpm and the car will gain speed at a normal rate too the speed I want but obviously at a rate that makes the drivers behind me not to happy. If I put it in neutral, the rpm's will go up to 4-5000 without a problem but nothing more. This did happen a few times this last summer and it seemed if I mashed the pedal to the floor for about 10 seconds it would fix/clear or whatever the problem, until now where I just can't get it to stop doing it. I have had it in the shop and they did a complete diagnostics check on the engine and found nothing wrong. Could this possibly be a torque converter issue? Plugged catalytic converter? I am open to any suggestions. Thanks in advanced guys.

Originally Posted by Hyrdgun

When I give it gas it takes off just fine until it hits about 20 mph and 2200 rpm's, then it falls flat on it's face.

What happens at 20mph? Does the engine run rough at all? Would you compare it to driving a manual transmission car and shifting from first gear to fifth gear instead of second gear? Does it seem to shift through all the gears fine but it just takes long to get up to those speeds?

SlowNA06, I have checked or replaced all the suggestions you gave me with the exception of the fuel injectors and the cat. At 20 mph/2200 rpm it just does not pick up speed anymore. It has that feel of still getting fuel but just does not want to go, but the tranny is not acting like it is slipping and the rpm's won't increase. If I sit in the driveway in neutral or park, the rpm's will get to about 5000. Doing the same in drive or reverse the rpm's will only get to 2200. I think I will try thegipper's suggestion of pulling the O2 sensor and driving it. A guy at work suggested doing the same but then also doing a back pressure test. Thanks guys

Definately sounds like a clogged cat.

Well, here is an update. I just happen to run into someone who was having the same problem, only on his Tahoe. Turns out that the sensors for the traction control were very dirty, and after cleaning them, it ran fine. I went out and unplugged one of the sensors, which turns off the ABS/Traction Control System, And wouldn't ya know, the car runs great. Now I just need to figure out which sensor is bad since I don't think I can pull mine out to clean.

sounds right, rpm limiting is a common traction control function, good info., would not have thought that