I had a blown head gasket had that fixed and the catalytic converter replace also had a fuel leak had it fixed and also the water pump. Now the car is running rough while driving and sitting like it want to shut off. When i start to drive it starts rough then smooths out and the check engine soon light starts blinking then stops. I was told it could be the injectors by one person another says a misfire, the spark plugs and coil pack is bad oh and O2 sensor. What could it be?

Cars & Trucks - Pontiac - 2002 Pontiac Grand Am SE