Q: could a 2002 2.0L Mazda Protege transmission fit on my 2001 1.6L Mazda Protege?

Hello. The Mazda parts catalog transaxle part numbers for the two years you cite are different. Therefore, these two transmissions are NOT interchangeable "out of the box." Sometimes the differences from year-to-year relate to electronics or controls which you "might" be able to carry over from your 01 but that involves a lot of research and confirmation as well as risk.

Transmissions change from year-to-year and although they might look the same externally, they are essentially completely incompatible because of changes in the controls (TCM, PCM, etc.). Unless you are an experimenter or hobbyist, you MUST always match the year, make, model AND codes stamped on the transmission tag itself. As far as your present mechanical problem, the gas pedal acceleration problem has to be diagnosed before you can condemn the transmission. You could have an issue as simple as a problem with the linkage to the transmission (from the gear selection lever), which really has nothing to do at all with the transmission itself.