Engine Performance problem
2000 Pontiac Grand Am 4 cyl Front Wheel Drive Automatic 139000 miles
I have a 2000 Pontiac Grand am with 139000 miles on it, I was driving along and instantly it began running very rough with white smoke and raw fuel coming out of thr exauhst.I did a compression check and all cylinders are around 200psi. When I pulled the spark plugs #3 and #4 cylinders are flooded with fuel and appear that they are not firing.I replaced the complete ignition module/coil and wires and plugs, and also changed the entire fuel rail and injector assembly from a identical running car and still no change the engine does not knock or rattle just shakes very badly. When I plugged my code reader it showed a PO300 multiple cylinder misfire detected.