With most aftermarket exhausts for the QR aren't seeing huge gains that you would like to see, but people are still going with an aftermarket exhaust for looks and sound. You'll probably see better gains with all three of the mods together, as they work very well with each other. You can totally have your stock muffler and exhaust with your new CAI. Go get you some!black se r said:i was tellin my friends how i was thinkin bout gettin a AEM or Hotshot CAI on my 02 se r. then one of them told me i need to get rid of my stock exhaust and get a different because there's more air goin into the engine. is that dude right or can i get the CAI and still have my stock muffler and exhaust?