Heatshield ?
 

The heat shield below the down pipe has came loose
and has started to rattle.. any suggestions on how
to quiet the noise?

yup, pop rivets.

That sounds like the catalytic converter shield.

Typically it's welded on to begin with and over time and heat cycles it rusts at the welds. I have seen and done this many times. You head over to Home Depot/Lowes and into the plumbing section. They have super large metal clamps. (like for a radiator hose..but much larger). Get 1 or 2, go around the cat and shield. No more worries. ;)

aaahhhh ok that part... yeah mines doing the same thing

its below the down pipe, i can see it from the engine bay..
it sounds like the metal clamp idea will do the job.
thanks.. :beerchug:

*Moved to 92-99*