The ability of the Nissan spark plug to provide the necessary arc of electrical current thousands of time a minute is what keeps the internal combustion running. This ignition component is the last part in the delivery system that makes operating of the Nissan engine possible. The spark plug is a simple ignition component with no moving parts. It has a metal tip at one end with a hollow ceramic chamber that leads down to a metal electrode at the opposite end. There are very few ways this ignition component can be faulty on your Nissan. If the electrode becomes clogged with oil or fuel it is considered fouled and the spark cannot jump from the terminal to the electrode. Cleaning the Nissan spark plug is the remedy for this situation. The spark plugs electrode will also wear out over time because of the numerous times the electrical voltage has jumped to it in the formation of the arc. As the electrode wears out, the gap changes and the only solution for this situation is the replacement of the plug. One of the last ways a spark plug would not be able to function is if the ceramic portion of the plug is damaged in any way. The most probable time this ceramic portion can be damaged is when it is being installed on your Nissan engine. This is when the plug is accidentally dropped for some reason. An impact with a hard surface can cause the ceramic portion of the spark plug to develop a hairline crack. This will render the electrode at the end incapable of receiving the electrical charge causing the plug to be in need of replacement.