I just noticed this a few days ago. When i first start my jeep and its cold it makes a like rattling type noise when i am accelerating the jeep for about a minute or so then goes away. The jeep wont make this noise if im just sitting there only under load. The only engine mods i have are a CAI and Mbrp cat back, anyone else have anything like this or have any idea what it might be. Also i have a 2 door 6 speed.
Thanks

 

could be you have a heat shield tack weld that's broken on the exhaust cross over - pretty common and it will do that. once warms, everything expands and enough so that the rattle stops.