Knocking noise - SOLVED!

Hey all. Finally took my car to the dealer again (04 GT). It was leaking a little tranny fluid, which they resealed the shifter. Want to upgrade it anyways, but figured its under warranty, might as well let the dealer do it free!

But....if anyone has seen my many posts about the rattling noise I've been experiencing, first time dealer said heat sheild...I couldn't find a loose one...this time, the tech, manager, and shop foreman all acted like they couldn't even hear the noise. I said...hold on...drove up there...and within 2 revs...said "there ya go." They brought it back into the shop...and after several hours, tell me ....here it is....wait for it.....a BAD CAT!

Sooo....if you have a rattle that rattles under most conditions, especially after warming up, then maybe bad cat converter!

Thanks!