The spark plugs in your Toyota Sienna need to be checked and replaced every 30,000 miles. The spark plugs provide the spark necessary to ignite the fuel in your Sienna's engine. If there is not a sufficient spark, then the engine will not run, or the fuel will not burn completely. Replacement spark plugs for your Sienna can be purchased from any auto parts store. You'll need to make sure that you know the model year of your Sienna so that you get the correct plugs. Also, you'll need a special tool called a spark plug socket. This type of socket is sold in auto parts stores and has a rubber lining that grabs onto the end of the spark plug inside the plug well in the engine.
Connect the spark plug socket to the socket extension.
Open the hood and pull the spark plug wires off the top of the engine. You may need to wiggle them back and forth while pulling up on the plug wires in order to remove them.
Lower the spark plug socket into the engine and push the socket over the top of the spark plug.
Turn the spark plug counterclockwise with a socket wrench to loosen and remove it from your Sienna's engine.
Pull the old spark plug out of the socket and insert a new spark plug into the socket with the electrodes facing out.
Lower the spark plug into the engine and thread and tighten the spark plug.
Slide the plug wire down into the plug well and push it over the top of the spark plug until it seals the plug. The wire should fit nice and snug over the spark plug.
