Wow, must suck having to worry about the legality of your car on the roads in CA.

Maryland is somewhat strict, but a friend of mine has an 02 Mustang GT with 3" straight pipe exhaust from the headers to the tail, and passed emissions with flying colors. Oh yeah, sounds like a shrimp-boat going by but hey, it's state-approved. Personally, I condone the use of a catalytic converter on any car that came with it from the factory.

Sorry, I am sure some people from CA will promptly respond on how to fool the system, or there might be perfect law-abiding citizens and suggest legal exhausts with the certificates for your car.

Greddy has a couple with certificates. www.greddy.com