Started my car today and noticed a buzzing coming from the exhaust pipes under the car, almost as if a piece of metal has broken off inside the exhaust and is flying around crashing into the sides of the metal. The name for this piece has slipped my mind. But its the pipe that runs from the exhaust pipe in the back of the car to the front of the cars headers. The noise seems to be coming from right under where the driver sits. The cylindrical exhaust piece right under the drivers butt basically. Sounds like a rock or piece of metal is vibrating around in the metal cylinder. Any idea what this could be? And what should I do to fix it? Whole new exhaust system or could I buy a part specific piece? Could I take it off and remove whatever is vibrating around in it?

Ill try to attach a video sound clip tomorrow if that helps.

 

Jack up the car and check your catalytic converter heat shields to see if they're loose or have rusted apart. If they're loose you could use a hose clamp and clamp them together, but it's really a good idea to replace those when they go to avoid heating up whatever you're parked on (like dry leaves ) and the floor of your car.

When I had a bad exhaust leak it caused a rattling as well, so just check for any rusted parts/holes.

 

Did it sound like a loose bolt had gotten loose in your exhaust system? because thats what mine sounds like. Ill check it out tomorrow

 

When I had an exhaust leak it just vibrated the whole pipe and muffler at 4500+ rpm and made it all rattle, so I doubt that's what you're running into.

I've never personally had a cat shield go out on me so I can't say for sure what it sounds like, but there is one near where the driver sits, so that's the first thing I would check.