Well, the car has been downshifting between 4 and 3 for no reason even when the car is at operating temperature. It is usually pretty quick at shifting back up but sometimes it wont shift up until it gets past about 4.5 RPM.

After I replaced the thermostat it didn't do it for a long time but in the past month it started up again. I had the tranmission filter and fluid changed too. There is under 108,000 miles on it and it doesn't shift hard or slip at all. The two mechanics I went to said that my computer probably had something wrong with it and thats why I wanted to get a new computer for it or have it be reset somehow.

Has anyone else had this type of problem? If so, any advice would help a lot.

Thanks,
Matt