ok this topic applys to about 4 different forums so hell, ill post it on all of em, sorry if you are reading this twice, or three times heh....sorry for all the questions/problems lately at that .....ok so i figure ill move the post over here, mayb e someon can help....plug gap is set at .45 , all exhaust is tightened, timing has been advanced from 0 -2-4-6-8-10-12, nothing helps , whole ignition system is new, coil cap dist rotor ignition coil plugs and wires. the backfire only happens on a de-celleration , lets say after i go 60-100 mph on the highway....when i start de-cellerating, itll backfire...liek a shot gun. there are no leaks on any hoses anywhere, ....--every sensor is new as well....i have no power loss at all. any ideas?