A: The spark plugs are located in the center of the valve cover(s). Access to the rear cylinder bank spark plugs on V6 models requires removal of the upper intake manifold. The tools necessary for spark plug replacement include a spark plug socket which fits onto a ratchet, various extensions and a gap gauge to check and adjust the gaps on the new plugs. A torque wrench should be used to tighten the new plugs. When replacing the spark plugs, purchase the new ones in advance, adjust them to the proper gap and replace the plugs one at a time. Be sure to obtain the correct plug type for your particular engine. Allow the engine to cool completely before attempting to remove any of the plugs. These engines are equipped with aluminum cylinder heads, which can be damaged if the spark plugs are removed when the engine is hot. While waiting for the engine to cool, check the new plugs for defects and adjust the gaps. The gap is checked by inserting the proper-thickness gauge between the electrodes at the tip of the plug. The gap between the electrodes should be the same as the one specified in the Specifications. If the gap is incorrect, use the adjuster on the gauge body to bend the curved side electrode slightly until the proper gap is obtained. All models are equipped with individual ignition coils which must be removed first to access the spark plugs. If compressed air is available, use it to blow any dirt or foreign material away from the spark plug hole. Place the spark plug socket over the plug and remove it from the engine by turning it in a counterclockwise direction. Compare the spark plug to those shown in the photos located on the inside back cover of the book to get an indication of the general running condition of the engine. Apply a small amount of anti-seize compound to the spark plug threads. Install one of the new plugs into the hole until you can no longer turn it with your fingers, then tighten it with a torque wrench or the ratchet. It is a good idea to slip a short length of rubber hose over the end of the plug to use as a tool to thread it into place. The hose will grip the plug well enough to turn it, but will start to slip if the plug begins to cross-thread in the hole. Repeat the procedure for the remaining spark plugs.