My exhaust CATS are clogged up. I want to do away with the CATS. I want to replace them with straight pipes. What impact if any will this have on my 1985 RX7 GSL 12A?

 

Can't hurt anything since it's not a turbo motor, but replacing all the cats with straight pipes will make it loud as hell, and give the car a bit more pep, but if you need to pass a state emissions test, that will be a problem. Also, the exhaust will smell stinkier and the car might spit fireballs out the tailpipe if you lift throttle after hard acceleration. Since you're in MD, getting historic plates solves the emissions testing problem. For the noise, you might want to consider one of these Racing Beat complete systems which includes a presilencer; it will be louder than stock, but the sound will not be as obnoxious as running straight pipes.

Exhaust System for 84-85 RX-7 12A Man Trans - Racing Beat