I have a problem with my car backfiring, sputtering when lights on, chugging, and no acceleration with more backfire when depressing gas pedal, my muffler blew off the other day also, i replaced the rotor, distributor cap, wires and spark plugs, during this time, and my muffler still blew off i thought it was timing and i believe i have the timing set correctly as of yesterday with out a muffler of course. and it idles good now, but as soon as i put it in gear and try to drive it it starts to backfire and sputter and sounds like a boat in water, it was a slow just started to getting extremely worse the seems like the more i started to replace parts. i read codes with odb1 and than cleared them, there has been no check engine light and no codes except e52, e53 and e98. please help. can i set my timing correctly without a muffler on it? and if the timing is correct how come it still runs like crap, i cant even drive it.