Well since imma be boosting in a few months, id figure ill need a new cat. I'll most likely get a Carsound cat but I dunno what size is best for my application? Since im going turbo, Im thinking 3 inch is good? But is that too big? or should I just get a 2.5 inch? I have a Greddy EVO exhaust system btw. I have a 02 Accord 4cyl.

So what size cat should I get? and NO I dont want a test pipe cuz I still need to pass emissions .