I hate the rattle

I have a very annoying rattling sound coming from under my truck (mostly right at start up) im not sure but it sounds like its coming from the exhaust or the cats or something can anyone help, thanks

 

i had a similar problem to you...turns out i had some pebbles stuck in the little shield that is bolted over the second cat on the drivers side.

 

I'd guess cats man, hope you can get it figured out ASAP

 

alright, ill check it in the morning, thanks

 

Does it rattle every time you start it? Why not get under the truck while you have a buddy start it and pinpoint the problem? There are literally dozens of things that could rattle underneath these trucks. Having someone diagnose it for you over the internet is very unlikely.

 

Do you have a cold air intake? sometimes those things vibrate.

 

Something else to check is the catalytic converter cover. I had another vehicle that did the same exact thing and it was the cover. seems one end had rusted loose causing it to rattle against the converter and it only happened at start-up

 

I had a rubber bushing once that split in two and was rattling the exhaust @ start up.................