A little history: When I bought my car someone had already replaced the cat with 3" pipe. The muffler went bad, so I replaced it with a big dynomax and ran 3" pipe to the fake cat. All the smog stuff is gone, and I'll eventually have headers. However the exhaust rattles now and doesn't sound good and I'm fairly sure there's a leak somewhere.

so...

ideally I'd just have headers and 3" pipe straight back to a decent muffler, but I really wouldn't mind being emissions compliant and would spend on a good cat but only the straight-through variety NOT with the air crap. Has anyone had prior experience getting someone to work on a car to restore emissions legality? Will they even do it? I know it technically won't be "legal" because the stock setup is altered, but my money says I can be at least as clean with a good aftermarket cat by itself as with a stock replacement and the air crap. Do any companies maybe sell an entire setup?

Thanks a lot for any help or advice