ok so this sound is driving me aboslutly nuts, it sounds like my truck is gonna die, its the heat shield directly on the cat, specificly the upper one, well i used a c clamp for a wile, but went off roading yesterday, and it disappeared, any other ideas? and products besides welding?

 

Mine original cat did the same thing and it seriously got on my nerves too. I welded mine, but I don't see why you couldn't just shoot some sheet metals screws through the upper and lower flange on the shield.