Does the dealer have to take my car back in Kentucky the next day?

I bought a 93 Pontiac Firebird from a used car dealer today. The car was a little scratched but otherwise seemed fine. I had looked at it before and really wanted it. I test drove it and everything seemed fine - a few rattles, but I expected that from a Firebird. Long story short by the time I've driven it home and around a little, it's quite apparent there's a grinding of some kind in the motor or transmission. Also, it seems one of the wheel bearings is going out. This is on top of other nuances wrong with the car. Also, come to find out, the catalytic converter has been chopped off. I don't want the car anymore, and I was wondering if the dealer had to take it back if I brought it back? Isn't there a 24hr rule or something? I'm pretty sure he screwed up by selling it to me without the catalytic converter anyway, but other than that am I in the green to get my money back?