I went 4wheeling tonight in my truck and now from 2000- 2500 rpms the exhaust or something rattles pretty loud just those rpms though. I'm thinking cat is falling apart or heat shield. any body else had this problem

 

my wifes Expedition was rattling she called me in a panic. when I got home I cranked it and rolled up underneath the passenger side. bad cat. If youv'e ever owned a Dodge you would usually have this problem at 27k miles or so. she's got 68k on the Expedition. I stepped on the gas and the rattle went away, Just lettin her know it's about time for a new one.

 

go out in the morning and check the exhaust once it's all cold. you most likely have mud packed up along the exhaust

I've gotten mud caught between the heat shield and cats before. rattled something fierce until I blasted it out.

on the other hand, when mudding around, you spend alot of time with full throttle for short periods. This dumps alot of fuel...which doesn't get burnt...which ends up in the cats...which then clog up, or overheat...and then are dead and sometimes make noise.
FYI: Federal Warranty on Cats for 8yrs and 80k miles or something ridiculous like that. Check your owners manual for the exact #'s before you pay a dime

 

Went out this morning and found the heat shield in front of the cat had broke a weld so i just ripped it off good to go now. thanks for replies

 

glad it was easy, and more importantly, it was cheap

 

Well maybe so on the cat. I had a v-10 and got rid of it for that same rattle noise, down in the engine.

 

You just find any ol reason to get rid of a gas and buy a diesel don't you Sam? Op you better just sell your kid hauler and get a "real" truck (a diesel) because Sam had the exact same rattle that he heard through your post but his was his engine giving out.... Wow