I got a 2001 dakota 4.7 and I've had this noise haunting me forever. After the truck is warmed up for 5 minutes it makes this terrible rattle only when I give it gas and the rpm's are below 2300. When I dont give it gas the truck makes no noise and sounds perfect. As soon as The rpm's reach 2300 the noise goes right away. Ive checked everything, all hangers, the cat, heat shields cant figure the dam thing out. Its sounds like its comming from right above the tranny. PLEASE HELP ME

 

Guessing here as I haven't seen your truck - but I'd say its the Cat/converter. There is a brick on the inside of the converter that once killed can brake loose & can vibrate like heck as the gas pressure changes.

Its located just on the top side of the tranny.

By themselves they are not that expensive - but I'm not sure what one would cost to be installed.

 

Ya I actually have no cat I cut it off because I thought it was that but thnx for the help