[Backroadwarrior]

Trust me, they are full of S??t I have had magnaflos on every type truck you can imagine, including my '04 Titan, and I never had a problem with them. I have cut one open, and there's nothing to fail inside of it. Plus they are stainless steel. So they don't know what they are talking about apparently! It sounds like a result of vibration. Kick the tailpipe and see if you can duplicate the rattle. If so, get someone to help you so you can crawl under the truck an find it. Check the heat-sheilds on the converers to make sure they are tight. But don't trust those amatures.