Also just so u know if u take all of he cats out, i have heard that people are getting some nasty exhaust sounds. If i remember right they said its really raspy and ricey. Some body did say if u replace the header and the cat to leave the resonator and that will quiet it down

 

You can't go to the website yourself and look?

And I also second the raspy sound once you start removing stock piping. Header removal makes the biggest change in sound; it increases both the pitch (higher sounding) and volume (louder sounding) of the exhaust. I had 2.5" piping from the downpipe back with only the resonator in my catback and the exhaust was ridiculously loud and once it got around 3500 rpm you could hear it get raspy.