Before you begin
Every day you use your vehicle, the engine goes through thousands of combustion cycles to keep it running. A key part of this process is the spark plug, which ignites the air-fuel mixture inside the engine. Over time, spark plugs wear out due to heat and carbon buildup, which can lead to rough idling, reduced fuel efficiency, and misfires. Replacing your spark plugs is an important part of routine maintenance that helps keep your engine running smoothly and efficiently. Before beginning, ensure the engine is completely cool to avoid burns. It is also recommended to disconnect the battery to prevent electrical issues while working. This guide demonstrates how to replace the spark plugs on a 2013–2018 Nissan Altima 2.5L 4-cylinder engine.