Now this sounds really bizarre to me. I've always heard that catalytic converters need to be between the exhaust manifold and muffler in order to work properly. Are the inspectors getting over on the law by strictly adhering to the letter of the law and not the spirit of the law, or would they be in trouble if the state pencil pushers saw them doing it? Since I was a kid I've also heard of cats being notorious for starting fires in fields and grassy areas because they get so hot. If they work just as good post-tailpipe, I would think that's a safer place to locate them, not to mention easier to change out, in addition to getting passed by the inspectors.