Sometimes I get a backpressure pop when shutting my engine off ! and sometimes going down the Road When cold ! Is this Normal ??? I figured shutting down is normal. But going down the road !

 

I've never had that happen driving or shutting down.

 

Same here; I'd have it checked. I haven't had any strange noises with mine at all since it was delivered in Feb.

 

FYI, Just got back from the dealer, the Chirp, Pop sound was caused buy the Oil blow by tube that was extendened, causing back pressure. They removed the Tube that was extended to the cab, now I hope I dont get oil smell in the cab, or I will have them put another one on.