I got burned by the stupid new cat law as well. The old way of determining the type of cat you needed was by referencing the engine size, vehicle weight, and original emissions requirements. Now that cat has to be listed in the states database as being made for that particular vehicle. My problem is that my 1981 Jeep CJ5 has a 1987 Ford Mustang engine in it (done properly and legally and issued a state emissions sticker by a referee). It needed a new cat, and not even CARB themselves could tell me what cat would be legal since there is no listing in the database for 1981 CJ5’s with mustang engines. I had it off the street for 2 years before I gave up and registered it in Texas. The other annoying part is that even without the cat, the Jeep runs cleaner than it did with the original engine.
