Rattle noise at engine shut off/96xj/4.0/AW4/242

I get a rattling noise coming from under the hump in the floor right between the two front seats every time I shut the engine off. I've searched the forums, I got under the old gorilla and yanked on some stuff, and can't find the problem. Transmission mount is good, tranny and t-case don't move, muffler doesn't wiggle too much, I'm at a loss. Anyone had this problem? I can see there is like a wing nut thing attached to the e-brake cable (I think) that looks like it could rattle against the floor board but it really sounds too loud to be that little thing. Any ideas fellas and fellettes?

I'd check the exhaust hanger that's right above the crossmember on the passengers side. Mine had broken off, but still looked intact. Whenever I started or shut off the engine it would make a rattling noise that was exactly as you described.

i had a broken flex plate on a cheby that did the same thing till it exploded on the freeway a few weeks later. might wanna take a peek and check that

How many miles do you have?

Tried hitting the cat?

i have tyhe same kind of thing..... i have pretty much disregarded it as a heat shield rattling..... meaning: everything still works so i am too lazy to look

Thanks dudes, i'll get under there and check those others, thanks for the input.
Just got a new cat, at 118k, so it's just some little pain in the buttocks i'm going to have to hunt down.
Have a good one!