My truck and a friends when we drive you hear something like a crackling sound more like a exhaust leak but we smell nothing.
We went and sat at the dealer to watch the trucks they work on and they had the same sound. Just trying to find out if this is normal.

 

A couple of question....1st is it throttle on the off really quick?? If it is what you are hearing is grabble. You know the sound that V8s make when you get off the throttle quickly(kinda sounds like a pop pop pop sound).

2nd At idle if it is doing it then it is a caculated "misfire." Meaning that the computer has starved the engine of fuel causing it to run lean with a severly retarded spark. Either way if it doesen't kick the engine light on its usually not a problem.

 

The sound is very light when idleing then when i am accelerating slowly or fast it gets louder. Would the small misfire be a vaccum hose problem? Cant seem to find any repair stuff on the net lol. Guess ill have to stick with a haynes manual when i go out of town.

 

Of all the 30 or so Ive taken apart, they all have louder than normal exhaust, even when its brand new.