Cat converters

They would not be smog legal. You need the exact correct parts in order to pass inspection.

Rite now cats are completely cut off and replaced with straight pipes. They were that bad. Is there anywhere to get used cats

Crown Vic exhausts fall into the following year ranges; 92-94, 95-97, 98-02, & 03-11. As long as both are Interceptors you should be good. It's illegal to sell used cats (Federal and State laws prohibit it), so don't expect to find any online. You can try a local salvage yard for exhaust parts and pipes, but they can face steep fines if caught selling a cat. You're stuck buying them new or getting them off a parts car.

There is a thread on cleaning catalytic converters as long as the structure is intact. YouTube scotty Kilmer catalytic converter.