Hey guys, iv been reading around the forum for a while now and checking out some online stores but there are way too many choices between a Cat-Back and a Cold Air Intake System. My question is this, for the intake i like the Injen SP Cold Air System, would you say this one adds the most hp? Now i have no idea about the cat back as there are way too many and iv read alot of good things so il ask this, which is the loudest when installed and shows a good horsepower increase? Im leaning towards the Fujitsubo Legalis-R. mainly because than i can get the Fujitsubo Super EX Manifold and the Fujitsubo Y-Pipe. any comments on this catback for loudness and horsepower gains? thanks guys