well, sorta, go to the library, look up the wording of your offense, and go from there.
silverstreakin is kinda right, when your OEM muffler rusts through you go to the muffler shop, and they don't replace it with an OEM... they replace it with an aftermarket.
The ES oval mufflers seem to be a popular option, make sure you have a resonator, you're basically looking at a custom setup, I think only thermal research offers 2.5 and up.
Anyone have any first hand experience with the es oval?
-PHiZ