2002 Pontiac Grand Am GT, I changed the spark plugs?

I have a 2002 Pontiac Grand Am GT 3.4. I changed the spark plugs on it just as a routine maintenance item. How important or critical is it that the spark plug wires be changed also? They are not damaged, or cracked and the inside that snaps on the spark plugs are fine. The car has 91,000 miles on it and they were the original spark plugs so i would assume they are the original wires as well. If they are still ok is it nessecary to change them or can I leave them as is? Thanks2002 Pontiac Grand Am GT, I changed the spark plugs?As a rule, I change the wires when I change the spark plugs. The wires internally deteriorate, so they need to be changed.2002 Pontiac Grand Am GT, I changed the spark plugs?If there is no damage to the insulation or the connectors on your plug wires and the car is running ok, then you don't need to change the plug wires yet.2002 Pontiac Grand Am GT, I changed the spark plugs?Run the engine in near darkness, and then look and listen. If you see little electrical arcs, or hear a snap-crack, there is high-voltage electrical leakage. Of course, running the engine at idle doesn't exercise the ignition system very hard, so you can add something to the test by spraying the plug wire ends with clean water from a household spray bottle.



Another test: With a jumper wire, ground the metal shank of a screwdriver that has a well-insulated handle. Then, run the tip of the screwdriver along the length of each wire and all around at the coil and plug boots. This will often produce an arc from the wire to the screwdriver.



Now look at the wires under good lighting. If they are damaged by abrasion, oil-soaked, cut, burned from contact with the exhaust, or have a dried-out look with heat cracks, it definitely shouldn't be a surprise if you see arcs in the dark under some conditions. However, if they look bad but there are no arcs, do a resistance check.



A conventional plug wire has a resistance of 10,000 to 15,000 ohms per foot of length--if it's measurably higher, the wire probably is bad. An absolutely failed wire will have a hairline break somewhere, and the resistance will be infinity.