It is impossible to drive a car with a missing spark plug, since the plugs are essential to the car starting in the first place. Spark plugs work to put the car's pistons into motion.
In time, spark plugs become worn or corroded, which can hinder engine performance. Once a spark plug begins to foul, it can cause noise under hood, a lag in acceleration and poor fuel economy. If the spark plugs give out completely, the car can fail to start. It can also cause irreversible damage to the engine and other components. Replacing the spark plugs in this instance is vital.