Should all ignition coils be replaced at the same time?
No, but the spark plugs should be. Aged and misfiring plugs or wires along with moisture induced corrosion on the wires/plug boots/coil terminals is generally what kills the coil.
Should all ignition coils be replaced at the same time?
No, but the spark plugs should be. Aged and misfiring plugs or wires along with moisture induced corrosion on the wires/plug boots/coil terminals is generally what kills the coil.