How to Change the Spark Plugs in a 1999 2.4 L Altima
- 1). Check the gap on all four new FR5-AP10, or equivalent spark plugs, using a spark plug gap tool. Nissan recommends that the Altima's spark plugs have a gap of 0.037 to 0.041 inches. Replace any incorrectly gapped plugs for new ones, as these platinum-tipped plugs are not adjustable.
- 2). Open the Altima's hood and locate the spark plug wires on top of the engine. Remove one spark plug wire by grabbing the thick, rubber boot on the engine side of the wire and pulling upward with a twisting motion.
- 3). Inspect the disconnected spark plug wire for any defects, such as brittleness, cracks or extreme visual aging. Replace the spark plug wires as a complete set if any defects exist.
- 4). Remove the old spark plug, using a ratchet, 6-inch extension and a spark plug socket. Pull the old plug from the spark plug socket and insert a new plug. Hand-tighten the new spark plug into the engine, using a spark plug socket and 6-inch extension.
- 5). Connect a torque wrench to the 6-inch extension and spark plug socket, and apply 14 to 22 foot-pounds of torque to the spark plug.
- 6). Repeat Steps 2 through 5 until you replace all four spark plugs.
- 7). Close the Altima's hood.