Hi just got my first impreza new MY03, 400 miles done so far and i'm going to scoobyclinic next week for exhaust upgrade and just trying to decide wether to completly de-cat or just center will be getting ecu upgrade also when run in, will cats meke a big difference to performance and advice appreciated

andy

 

i personally would wait a few months before caining it full decat on a brand new engine, if its only done 400 miles.