Do I need to replace the spark plug when replacing a coil?
Documented on the 2012 Ford Mustang GT build
Published February 26, 2026
Not always, but it's a good idea to inspect the spark plug.
Full Answer
Not always, but it's a good idea to inspect the spark plug. If the plug is worn, fouled, or has high mileage, replace it while you have the coil off. New coils on old plugs can mask underlying plug problems.
Documented In This Build
Related Knowledge
What torque should I use for the coil mounting bolt?How do I know which coil is bad?Can I clear the code and drive without replacing the coil?How do I know if the PCV grommet is bad?What causes oil to fill the spark plug wells?Can I drive the car if the plugs are covered in oil?How often should I clean the fuel injectors?Can I use a pour-in fuel additive instead of an inline cleaning kit?
Related Parts
Ignition coil pack (single cylinder, coil-on-plug)
$100
Replacement spark plug (recommended)
$12
Dielectric grease
$5
Related Tools
Torque wrench
OBD-II scanner / code reader
Ratchet
10mm socket
Extension bar
Spark plug socket (5/8" or 13/16")
