I have a 2001 Grand Am SE 2.4 liter automatic. Last winter, it started idling high after a cold start (around 2500 to 3500 rpm) and then would drop to 1000 to 1500 rpms within 15-30 seconds. It also started shifting strange, mostly from 1st to 2nd and 2nd to 3rd gears (automatic transmission). The car would rev to 3000 to over 4000 rpms and then shoot into the next gear, unless I babied it and feathered the gas pedal, it wasn't so harsh. I took it into a repair shop, no codes came up and they weren't sure what it was. I replaced the tranny fluid and TPS, neither did the trick. Then I had a "new" used computer put in, which seemed to do the trick.
Then within the last month, it started having the same symptoms again. I did have a code on the OBDII, which was for a small EVAP leak. I replaced a hose (attached to the MAP sensor I believe) and then the TPS (again, even though I had replaced it less than a year ago). Neither fixed the problem. My question then, is it likely that a 2nd computer (PCM I think it's called) go bad in my car within the same year? Or is it something else, even something that could make the PCM go bad in the first place? Any help would be greatly appreciated.