Mine pops bangs n flames on over run when shifting gear quickly or letting of the throttle U can do it when driving slow just come of the gas then literally put your big toes worth of pressure bk on the throttle n it will allow just enough fuel through to pop bang etc if your motor does it all the time regardless of how it's being driving I'd say there was an issue with the fueling as u don't want your car running to rich cuz u can do just as much damage that way as u can running lean ,