OK guys I have had my OEM cat on for a while now with the headers and it is not louder than it was before we installed the headers. My brother gutted his cat and I love the sound of his 93 Z28 now.

My question is: Can I take the exhaust off it and drill out the rear baffles and then blow the crap out by starting the car? I don't want to have to pull it off at the y pipe as it is connected by clamp and slid in. Let me know.

not really so much an answer to your question but more of a comment - i have a '93 Formula that had the cat gutted and it absolutely makes a substantial difference in the sound of this car for some reason. it almost sounds like an aftermarket exhaust. i guess that shows you how restrictive the stock cat is on these cars. not long afterwards, they switched to dual cats and the horsepower numbers started to climb. coincidence? hmmm....

now about your question, i don't know what the best method is for doing the actual gutting (previous owner did it on mine) but getting it off the car should be pretty easy. i'm assuming you have a single cat car, in which case you'd just unbolt it from the downpipe, loosen the clamp if there's one present and slide the cat off of the Y-pipe. might have rusted bolts or fittings so it would help to have some liquid wrench handy (or a torch worst case scenario) but other than that i think you can get it off there without too much trouble.

good luck,
~frank