Hi, i have a 2001 usdm bugeye wrx swapped with a jdm motor, but still the same ecu and it runs bad. The jdm motor is from a 2002 wrx i think. Can i straight swap the ecu? My ecu is a v2 but the pther one is a v3

I have a 2006 Wagon WRX with 85k Miles on the clock. The car is all stock. It has been running a little rough at idle and stutters under acceleration. After a stutter or two the car seems to pick up and pull pretty well. I have read lots of threads about similar problems and decided to check...