Have similar annoying rattle. Doesn't sound like ac clutch area. I deadend some of the heat shields from about cat back. I don't see any broken hangers, etc. I listened with my ear to the end of a dowel rod with the engine running. More rattle listening to dowel rod putting the other end of the post on the exhaust pipe near the engine than when I put it up to the clutch housing or transmission housing. Doesn't sound any different with clutch depressed or not. Haven't been able to see the exhaust all the way up to the engine yet. O2 sensors before / after the cat look okay. Is there anything else that could be rattling upstream of the cat? any other ideas?

 

could be the inside of the cat is goin to pieces. how old is it? there are guards that go around the spark plugs, could be one of those got bent into the exhaust or is lose and i think another guard on the exhaust manifold itself.

 

It's a 96. It could be the original cat. We bought it with 34K miles and haven't had it replaced; now at 160k miles. Thanks, I'll check into spark plug shields, etc. I'm looking into the 222 threads on the word "rattle"! Lots of them reference the cat. I'll have a lot more fun without the "car's falling apart" sounds!

 

catalytic convertes were designed to last ten years... this isnt saying every cat will fall apart after ten years but in emission classes thats what i was taught

 

Thanks for your help Toneman. Should I be getting a trouble code for the cat, if its falling apart? I am getting a code, but is related to EGR. I found some repair receipts for the car. All kinds of stuff replaced, but not the cat. Could be narrowing it down. Thanks.

 

not necessarily depening on placement of oxygen center is there is no sensor downstream of cat you will get no code

 

I had the same problem on my Cutlass. Just take a hammer, and hit the bottom of the cat. If it rattles, there you go! I thought at first, every valve in the engine broke.

 

I have notice my car makes a loud growling noise in first, but it gets less when I let off to shift. Once I shift to second there is a loud screech and the growling start all over again.

 

If you would take time to grease your tires once in awhile, the annoying screech will subside. Regular maintenance is a must. And after you grease your tires, floor it in 1st, and keep it there. Growling will stop suddenly. Mechanics comes easy for me.

 

eh what do you expect its a camaro