I have an 01 Grand Prix GT N/A with a almost new TEP transmission. The motor has about 160k miles on it with about 7k on the trans.
Recently I have had the radiator, new gaskets for both intakes, new upper intake, and the lower intake refinished to remove any buildup for a good seal. Which it improved my gas mileage and I believe fixed any vacuum leaks that I had but afterwards I have noticed what believe are probably the last few issues with my car. The power band has been inconsistent I noticed lately, for example if i'm slowly accelerating up a hill in 2nd gear in traffic I can feel it drop power for like a second or two and then pick it back up, just like it's jumping through the power band occasionally. Every 2 out of 10 startups it will just die without trying to idle or try and catch itself at the last second and fail but will work just fine next time it gets cranked. And the big side of the transmission where the torque converter is inconsistently makes almost buzzing sound off and on regardless of where the gearshift is at, I can definitely tell when it's doing it when at a stoplight because the shift from 1st to 2nd will be harder.
The trans has less than 7k miles on it and was built by TripleEdgePerformance, I sincerely doubt it's a problem with something in the trans itself because of that and it doesn't do it all the time and no common denominator either. I was talking to the guy at TEP and he said it sounds like it's commanding high pressure for some reason. I was thinking it's the computer going bad because these symptoms are the same as my trucks before it's computer died, I talked to the guy who plugged a reader into it to check for error codes and when it came back clean he told me that early 2000s GM cars really struggled with PCM issues. Any thoughts or advice would be appreciated!
