I have a 07 Impreza 1.5r which had a single outlet back box. I think from looking at the exhaust pipe the diameter was 2inch's which I took off from the first clamp ( axle back )and replaced with a standard 07 WRX twin outlet back box. The diameter of this looks like 3 inch's on the pipe. My question is... will this affect my air/fuel mix, would it be ok to carry out this mod without mapping the ecu. It is a bit louder but not too much so. I am just concerned about flat spots and engine running lean etc.
Sorry in advance for asking silly questions but when I was messing with cars years ago we use to have carbs.
Sorry in advance for asking silly questions but when I was messing with cars years ago we use to have carbs.
