The rear cats are at the rear of the car just before the chrome tips. I cut mine out and just put in a straight pipe. Changes the sound some, eliminates drone and supposedly adds HP. I make no claims on that but if you have added a CAI logic suggests it likely.


I believe Valk will attest to the sound quality of my NA after this simple and inexpensive mod.


Magnaflow and Borla websites both claim relatively huge HP gains. (20HP) I would be interested in comments from our esteemed friends north of 60' 18" N as well as others about that.


Rear resonators are supposed to stop "popping", at least according to Magnaflow. But I see no reason the square stock tips would change that if added. If all one does is add the magnaflow , or Borla, mufflers and front cats, perhaps retention of the back cats is indicated.


As for me, the occasional "popping" is not an annoyance.