got a 95 Z28 m6 with a ratling sound coming from under the car. sounds like a bad TOB but its rattling even when I engage clutch pedal. doesnt slip in any gear at any throttle and engages smoothly into gear.

 

They all do that. It's called the 'can of marbles' sound. My Corvette even did that by the time I got it home on the day I bought it and I thought it was coming apart and was all pissed off. But they all do that if you lug them off the line a little, no problem - it doesn't hurt anything so relax about it, LOL.

 

Found the problem, propped it on jack stands on all four corners and just followed the rattle to the cat, apparently it's an aftermarket HF type that just must be fractured material inside. No big deal, next week ill just have my muffler shop weld in a test pipe and might as well have him weld on my old magnaflow from my old 94.

 

Ok i was wrong then. Mine ate the aftermarket cat, too and it did rattle a bit. Good job finding the prob.