Changing ECU between cars?
(sorry about the long sentencing, wont let me hit return to paragraph) Hi folks, looking at a car that's got stage 2 mods, but not mapped to stage 2, I might be in a position to buy my old ECU back from my last car that had custom code stage 2 mapping on it. My old car was a 97 A3 1.8T sport, AGU engine, no aircon, with sunroof. New one is also AGU but a 99 on a T, has aircon, no sunroof with heated seats, and has stage 2 mods but is currently stage 1 mapped. I am wondering if I was to swap ECU's, would it be compatible with the new car? Cheers.