The almighty Pontiac spark plug is the engine component that ignites the explosion that your engine needs to run. The spark plugs ability to create an arc up to 6,000 times a minute on average is an amazing feat, without which your engine could not operate. There is a Pontiac spark plug for each cylinder on your engine. Each one creates an arc when the piston inside the cylinder below is at the top of its compression stroke. If the arc is created any other time, it will not combust the air/fuel mix at the optimum time and will have little or no effect on providing power to the engine. The different components of spark plugs in all Pontiac engines are basic and simple. At the top is a metal tip. This is connected to a hollow ceramic chamber that is connected to a threaded portion on the bottom. There is a small electrode in the center at the bottom. Also on the bottom is an electrode that protrudes outward and then over the other electrode. The gap between these two lower electrodes is where the electrical arc is created. The reason for the need to replace the spark plugs in your Pontiac engine is the electrodes in the bottom will wear out over time due to the electrical discharge they create. This widens the gap and a small portion of the electrode disintegrates. There is another way a spark plug might become inoperable. This is when they are being swapped out of your Pontiac engine by a technician. If, for any reason, one of them is dropped it should be replaced. The ceramic portion of the plug is durable but brittle. Impact with a hard surface can cause it to develop a crack making the entire plug faulty.