2003 Chevrolet Silverado 1500 - Spark Plug Wires

Why Are Spark Plugs & Wires Important?

Your spark plug wires or ignition cables carry power from your vehicle's distributor or coil to the spark plugs. Spark plug wires feature a boot at each end that connects to the coil, distributor, or spark plug, and has an insulated conductive core to safely carry the current without arcing. Spark plug wires are typically routed using looms or brackets to prevent them from contacting any metal surfaces, as this can cause wear and lead to grounding that can prevent ignition. Over time, spark plug wires and boots may be damaged by heat or with regular use, and this may cause poor conductivity or a complete lack of power reaching the spark plugs. If you're not getting spark to one or more cylinders, this could lead to misfires and rough engine operation that may point to a problem with one or more spark plug wires. When this occurs, the first step is often to perform a spark test to determine if the spark plug wire is to blame, or if the spark plug is damaged or no longer working as it should. It's usually recommended that you change your spark plug wires when you replace your spark plugs to ensure a complete tune-up and the best possible ignition system performance. Signs that you may need spark plugs and wires include an active Check Engine light, erratic idle, engine misfires, poor acceleration, reduced fuel efficiency, and increased emissions. Replacing your spark plugs and wires may not only restore your vehicle's performance but can also improve your fuel economy. O'Reilly Auto Parts carries replacement ignition wire sets, performance spark plug sets, new spark plugs, and other ignition system parts to help you make a complete repair.