engine shaking back and forth and exhaust sounds plugged ... could it be timing??
it's a pontiac sunfire, ... it's the girlfriends sisters car.. so you can imaging how much maintance it gets.....when it's at a idol, the engine shakes back and forth violently, it sputters and spirts like the exhaust is plugged..had a new muffler put on it , going to change the plugs, and try to re-set the computer, could it be a timing issue???also going to change the fuel filter if i can access it easily, could the muffler have been put on backwards