Car has been idling a little funny lately, noticeably at start up it will do little sputters here and there but sort of evens out as the rpm's drop. I don't know if it has anything to do with this noise though. I took this video after a 20 minute ride around town. Any ideas?

What's this noise? - YouTube

 

No idearssss????

 

bad cat?

 

Sounds fine to me.

 

Nah, there is a definite metal rattle sound there which was not there before. It does seem to be coming from the cat but I can't say for sure, doesn't sound as if it's coming from the engine. I can notice it alot when I'm next to a wall or something like in the D&D drive thru.

 

My thought was maybe a piece of the cat has cracked and come loose and its now bouncing around inside, but you wouldnt know until you took it off to inspect.