For 1998 and later models without a conventional distributor, the plugs are fired by two coil-packs mounted on top of each plug in the valve cover. The coil-pack serves two cylinders, with one cylinder having a boot from the bottom of the coil-pack to the plug, and uses a plug wire from the coil to the other cylinder. It is necessary to examine sparkplug wires before fitting new sparkplugs for safe engine operation. Look for arcing or sparks at damaged areas while visually inspecting them with the engine running in a darkened ventilated area; replace wires if they arc and check distributor cap and rotor when engine has cooled down. If you need to maintain correct order while inspecting each
Spark Plug cord individually number or mark tape can help you do so. Remove wire from spark plug, checking for corrosion inside boot and test resistance; replace wires if resistance exceeds maximum value. Make sure wire fits tightly on spark plug and clean length of wire looking for burns, cracks, or any other damage that would cause sharp bends. Remove wire from distributor cap or ignition coil checking for corrosion and good fit then put it back on again. Inspect all remaining spark plug wires making certain there are no loose connections between them and either distributor or spark plugs: replace as required. With distributors equipped models remove distributor cap, see whether it is cracked or not, look for worn out contacts, carbon tracks and burnt ones; ensure rotor is not spoiled by carbon tracks otherwise damaged parts should be replaced with new ones. Change caps one-by-one replacing an old one with a new one so as to maintain proper firing order when installing a fresh cap.