ok so I recently had to replace the pcm in my 97 cavalier 2.2 (with side feed injectors), but all I had available was a 98 pcm from a car with top feed injectors,.... part # on the case is the same, but it seems like the new pcm has some interesting effects on the power of the car.

The car use have some bottom end, and not too much at the top of the gears,..... now it's the opposite, car falls on its face till about (what sounds like) 4k rpm, then it starts pulling hard (for a base cavalier) till it shifts.

So my question is would the fuel and timing tables for a 98 pcm be different than a 97 with side feeds? Because it sure does feel like retarded timing, or over fueling to me.