I just picked up and '04 sti muffler for my '04 RS. Cousin told me that putting it on would make me lose horsepower. Wondering if what my cousin told me is true.? Sorry guys, I am new to i-club and is a first time owner of a suby. Can anyone provide real answers. Dont really trust my cousin>>>>.....

 

is ur cuzion on here if so whats his screenname and what size piping is it?

 

if its the axleback then I would say no...catback then yes cuz u losing back pressure