Cat-back Exhausts help improving the sound ?

Question

or do they also help improving the power ?

Answer 1

ypur question is a bit vague,but to improve sound just replace

rear silencer for a sportier one . you will find them in car modification magazines

Answer 2

Hi-flo cats improve the sound and performance if you change them along with the cat back exhaust, the cat back exhaust  if you use high flowing mufflers  will change the sound greatly.

Answer 3

depends if you get a stock type or a performance type. the performance type will slightly improve power. any auto store can help you select one. Just depends on how much you want to pay $$.