So I just got my car tuned and it ran great for a couple of days now out of the blue, if I give the car a rev, or just bring it up to 4,000 rpm in gear and let off I get the sound of a backfire would this have anything to do with the tune? If so any thoughts on what it might be?

Dan

 

if its happening out of the blue now a few days later i doubt its the tune...possibly plugs/wires? check for missfires.

 

The only thing weird is that I can hold it a 4,000rpm in and it does not have a miss it is only when I let off so I don't think it would be plugs or wires.