2 weeks ago failed NOX emissions test for what is believed to be a bad cat. Ended up buying a 2" Bosal cat for $100 at Autozone. After thinking about it I figured it was probably time to replace the rest of the exhaust which is ~ 7 years old. Was thinking of upgrading the stock muffler exhuast to a 2.25" turbo from fcpgroton for another $100. Well after reading the turbobrick forums I deceided to look into a 2.5" exhaust with a Magnaflow muffler and no resonator. Went to a local exhaust shop and got a quote of ~$200 to install a 2.5" custom welded exhaust with a 6" Maganflow muffler and chrome tip. This also includes installing the cat I got at autozone. Everything is aluminized steel.

How does this all sound? Is the 2" cat a good choice or should I consider returning the AZ cat and going with a 2.25" cat?