Well my friend wants an exhaust! he got a 2002 gts btw. So i told him y not get a custom exhaust with 2.5 piping from a muffler shop and get a muffler like a n1, 5zigen, or a tanabe! My question is how many of you out there have custom exhaust and does it give as much hp as it would a trd? its it tat much better getting a trd?