Unlike many vehicles, the Toyota 4Runner has coil packs that attach to the spark plugs and give them a spark. This configuration might look a little different if you are used to pulling off a boot to change spark plugs. But aside from having to remove a 10mm bolt from the coil pack, the replacement process is similar. You must remove the air intake hose to have adequate room to work, but the job is straightforward.
Turn off the 4Runner engine. Open the hood. Disconnect the negative battery cable.
Loosen the two hose clamps on each end of the air intake hose with the Phillips screwdriver. Remove the hose. This provides access to the spark plugs on the passenger's side.
Use a toothbrush to brush away debris from the coil packs and the area around coil packs. Unhook the harnesses attached to the coil packs by pushing the harnesses in on the sides. Pull the harnesses off the packs. Remove the 10mm bolt that holds the coil pack in place with a socket set. Remove one coil pack.
Use the spark plug socket, ratchet and extension to remove the spark plug. Carefully remove the spark plug from the engine. Clear away any debris that might fall into the spark plug hole.
Spread anti-seize on the threads of the new spark plug. Screw the spark plug into the engine. Tighten the spark plug with the spark plug socket until it is snug. Apply dielectric grease to the top of the spark plug. Place the coil pack on the spark plug. Attach the plug to the coil pack.
Repeat these steps for all six spark plugs. Have only one coil pack off at any given time to avoid placing it on the wrong spark plug.
Replace the air intake hose. Tighten the hose clamps. Connect the negative battery cable. Close the hood.
