Just a few questions about exhaust for a 03 GT... I was planning on getting an off road X pipe for my car, but I recently was talking to someone who said that the newer mustangs need the back pressure for the exhaust, so its not that much of an advantage to take the cats off. This didn't sound quite right to me, I think the more free flowing the better, but I thought I'd throw it out to everyone to see if anyone else has heard anything about it.