the catback will not net you any gains even if youre making a million horsepower. only change it if you want a different tone out of it. otherwise just leave it alone and run with it. these cars just dont make power from changing up the catback. its literally unheard of. yeah, you might pick up 5-7 whp if you drop the catback at the track if you have a full blown cammed and intercooled setup, but why make the car unnecessarily louder and uglier sounding for 2 whp when youre not really modded or 10 if youre heavily modded? it just doesnt make sense to waste money on it.