hi all, i have an 06 STI with PPP and want to know if taking out the cat and replacing with a decat pipe will do any harm to the engine, i dont mean the cat in the up pipe that comes from the turbo the one below it, will it make it run better or worse, also would i need a remap, honest opions would be nice, cheers steve

 

i have a Hawkeye WRX, from experience....

the first thing i fitted was the centre pipe and at a guess it gave me 2 maybe 3 horsies (it felt like the moment 3 or 4 people had just got out your car), i then changed the backbox not change to power... i changed the downpipe and whoosh Louder and faster 10/15BHP.

from that i would say there isn't major gain in doing it, but if your going to go for more power (new turbo ect) it id worth doing