Since he has a V6, why not get the MSDS headers, with the MIL eliminators and a sho shop y. Heckuva lot cheaper all together, and unless the shop he takes it too here in California are tightwads and know what they are looking for, he should be just fine.
If it's the main cat, then just get a new y pipe.
Kasey, where are you at in Cali? There are a handful of people around that could/might help you. Check out the California Section.
A new y pipe is a cinch to install. New headers are a roral PITA, but doable.
Mike
