This procedure applies to 2005 and earlier V6 models only. The spark plug wires should be checked at the recommended intervals or whenever new spark plugs are installed. Begin by making a visual check of the spark plug wires while the engine is running. In a darkened garage with adequate ventilation or at night, start the engine and observe each plug wire. Be careful not to come into contact with any moving engine parts. If possible, use an insulated or non-conductive object to wiggle each wire. If there is a break in the wire, arcing or a small blue spark will be visible from the damaged area. Secondary ignition voltage increases with engine speed, and sometimes a damaged wire will not produce an arc at idle speed. Have an assistant press the accelerator pedal to raise the engine speed to approximately 2000 rpm and check the spark plug wires for arcing as previously stated. If arcing is noticed, replace all spark plug wires.