Popping pipes (Vance & Hines)

[Asian Nightster]

I just installed Vance & hines SH slip-on, with a fuelpak and screaming eagle air flow. I did all the proper settings but I still have a popping sound when I decelarate. Can someone give me some advice on what to do. Also, when installing this combo does it give you better gas milage or does it take more gas with louder pipes.

thanks in advance

 

[glider]

Check your exhaust for leaks. The twisting of the throttle trying things out will use more gas usually.