so i have a pypes catted x pipe on my 2001 stang, i've only had the system for about a year and the cats have recenly started to rattle a lot. has anyone else had this problem, or is it just a fluke with my system?

 

What do you mean by rattle a lot? Are you sure that it's your cats?

 

what it sounds like is metal vibrating. i went under my car yesterday while it was running and sounds to me like it's comming from the cats, or at least in that area. there isnt anything visibly wrong, but i hear it sometimes when the engine is idleing, and all the time during acceleration. any thoughts?

 

I'm assuming that everything is bolted together tight enough on your exhaust? Sometimes bolts or nuts can come loose due to excessive vibration. Your exhaust might also be rubbing on something else metal.

 

yeah thats what i thought at first too. the cats came welded to the system tho, and i couldnt find any loose bolts. i'm trying to avoid taking to a shop if possible cause money is kinda tight.

 

complete guess but did you make sure there is enough clearance from the driveshaft? maybe its vibrating against it if you installed it to closely

 

that was actually one of the first things i checked, and theres plenty of room.

 

i did another check today. i tapped on the cats with a flash light out of frustration, and guess what, they make the exact same sound that i'm hearing when its running. yay for randomly hitting things.

 

the cats are turning to **** and the filtering media inside (platinum I think it is) is coming apart.

 

I have also seen gravel get caught in between the heat shield and the cat itself.