I've read other threads about removing or stabilizing the heat shields. I tried the trick with a sheet metal screw on the one shield that was loose and wobbly, but my rattle is still there. I figure that it's just as easy to remove them if they're not doing anything for me.

 

I'm talking about these on the exhaust pipes before the cat:

 

They can be removed. Just don't park on hay piles. I had several rattles and just today finally got rid of the last one. It took a number of worm drive hose clamps and nuts and bolts. The worm drive hose clamps work pretty well to stop the rattles.

I removed both from the "Y" of the Y-pipe after giving it a shot with worm drive clamps... they consistently needed to be tightened after a week or so, and I got fed up with it. I currently have both the pieces at the Y and those just after the cat clamped, and both still need to be removed.

 

As previously stated, just don't go parking in long, dry grass with a stonking hot motor.