Weird engine noise

I have a weird engine noise every time I step on the gas. Usually only happens when I step on the gas from a full stop. The noise sounds like a slight aftermarket muffler sound in the engine area, a slight rumble. I have no check engine light or codes. Anyone know what it could be? Temperature gauge is also fine. Truck drives fine overall.

 

I had this happen to me when only in reverse. Turns out to be common and easy to fix. It was the air intake tube rattling in the hole where it extends out the engine compartment. I folded a small peice of cardboard and wedged it between the cold air tube and the hole where they touched... Fixed.

 

Thank you for the reply, I noticed this was a common problem on the 2nd gen!

I guess when I changed the engine air filter that clamp got loose so i read online and they said to twist the air intake hose and retighten the clamp. The droning noise is now gone.