1997 Hardbody

Climb underneath. Check for rusted and loose heat shields in exhaust system.

I can't see or smell it from here. The only reason I suggested that is because I have a 97 PU and pieces of the shield are constantly rusting away. I had one that would rattle for a few seconds when I cold started the truck, but as long as the truck didn't sit long enough for the exhaust to cool down, upon restart, it didn't rattle. When I ripped off the offending shield, it never rattled again upon a cold start. If you start pulling off pieces, never park where there is a chance that something under the truck could catch fire. This is warned against even when all the shields are intact, but even more so when the shields are taken off.