Terrible RATTLE## please help

i got this horrible noise comming from my catalatic converter that makes my car sound like a wind up toy......
it rattles at idle then real bad as i inrease from 3500-6500 rpm.


i heard its the heat shield, shout i look under the car and try to remove it or fix it or is it the cat, do i need replacement??

thanks

Mine did that you need to tighten the bolts up on the sheild or get a new cat possibly because the outer casing may be loose.

Mine started doing that because my motor mount was loose on the front bottom.