How to Replace Spark Plugs in a Nissan Pathfinder

The Nissan Automobile Company suggests that spark plugs in a Pathfinder be replaced every 100,000 miles. Replacing park plugs at regular intervals improves gas mileage and lengthens the engine's life. In Pathfinder models produced before 2000, the spark plugs are easily accessed on the sides of the engine.
Difficulty: Moderate
Instructions
Things You'll Need
Screwdriver
Metric socket set with 16 mm spark plug socket
Socket wrench and extension
Anti-seize lubricant
New spark plugs
Tension tester tool
1

Allow the Pathfinder engine to cool completely. Do not work on a warm engine, especially if it is made of aluminum.
2

Gain access to the spark plug wires. For a 3.5 L engine, remove the engine cover and take off the air duct with air cleaner assembly. Disconnect the harness connectors and harness brackets around the ignition coil. Remove the electric throttle control actuator and disconnect ignition the coil harness connectors. Once these are disconnected, unscrew ignition coil bolts and remove the coil. On a 4.0 L engine, simply remove the ignition coil.
3

Grasp the boot of one spark plug wire. Twist it gently from right to left and pull it outward.
4

Unscrew and remove the old Pathfinder spark plug. Remove and replace each wire before moving on to the next wire.
5

Apply anti-seize lubricant to the threads of the spark plug and the wire boot. Insert the spark plug into the cylinder well and tighten it in place by hand.
6

Use a tension tester tool to find the exact tension of the spark plug. Adjust the tension to the specifications of the spark plug manufacturer, which is located on the spark plug's packaging.
7

Reconnect the wire and turn it until you hear it click and lock into place.
8

Repeat Steps 3 through 7 with the remainder of the spark plugs.
9

Replace all the items that were removed in Step 2 for access to the spark plugs. Start with the last thing removed and work your way back to the first thing removed.