Hey all thanks in advance for any help. I recently bought an 96 1500 4x4 with a 305. It runs and idles pretty darn good but under deceleration/ slow slow driving it seems to backfire/pop. Defenatly sounds like its coming through the exhaust. Only thing I know about it is he recently changed the plugs wires cap and rotors. Also has full dudal exhaust system on it. Any questions pls shoot me a line.