Rattling cats?

[LaFlavor]

I put an MRT catted H-pipe on the car roughly a month and a half ago. Recently, I've noticed a rattling noise coming from the under the car right around where the cats are located. It gets louder as the throttle opens up, but you can often hear it even at idle if you are laying down next to the car. The noise is definitely louder on the driver's side.

It sounds a little bit like something might be loose, but I crawled under the car one evening, and couldn't really move anything by hand. It's possible to get some movement between the two pipes at the crossover, but not much.

I don't have a whole lot of experience with this stuff, is there a reason the catalytic converter would be rattling?

 

[Predatorbird]

Try pulling off the heat shields. i had the same thing happen to me on my last car and I just removed the heat shields.

 

[mu22stang]

I guarantee it's the heat shields. Same thing happened on my MRT catted H. I removed them after trying to reweld them 3 times.

 

[JetmechF16]

I just had the same problem a few months ago, the honeycomb inside the cat is probably falling apart. You can buy new cats from MRT for about $50.

 

[LaFlavor]

Thanks for the replies. It was the heat shield on the driver's side cat. I just put a couple hose clamps around it for now. If it starts acting up again I may remove it entirely.