So i thought it might be bad gas, but it isn't getting better. It only backfires on decelleration, and it isn't like one snap, more like several bangs. valve lash is ok, i can't hear any exhaust leaks, i have a 172 main and the stock pilot, no screw adjustments, i run cam2, and performance wise there is no other problems (no deadspots, no studdering, has great throttle response). anyone have some suggestions? thanks.