Is it time to change my cat-converter? (Video clip inside)

[PRECORD]

Not sure if its my cat-converter making that kinda vibrating/rattling sound. But im sure its coming from under there. What else should it cause when my cat is done?

http://smg.photobucket.com/albums/v9...t=MOV02108.flv

[Losiracer2]

that could just be the heat shield. It's held on with 4 screws, maybe a couple of them aren't on tight enough and are rattling? Thats my guess