Post by
Ever Victorious »
https://forums.nicoclub.com/ever-victorious-u44595.html
Sat Oct 13, 2007 8:56 pm
Axle Back: replaces the rear section and muffler, called such because it usually starts at the rear axle and goes to the back of the car. These exhaust systems will change the sound of your exhaust note, but will not change performance characteristics at all.
Cat Back: Replaces the entire exhaust system from the outlet of the catalytic converer all the way to the back of the car. These exhaust systems will often drastically change your exhaust note, and can add small performance gains to your car. These gains are amplified by adding other "breathing" modifications, such as a Cold Air Intake, headers, and high-flow cat.