Cat-back exhaust..what is it?

[94_AcCoRd_EX]

Originally posted by OPAKRACING
When i do the whole exhaust, i usualy refer to the headers, and the a cat back system....tho you can buy racing catalitic converters....which is basicaly a legal strait through pipe....(i think, correct me if i'm wrong bout that)

I believe its only legal to change out your cat after 100k miles or if a mechanic certifies that it is damaged and needs replacing.