Part and system guide
Spark Plugs
Spark plugs ignite the air-fuel mixture inside gasoline engine cylinders.
What it does
Create the spark needed for combustion at the correct time.
Failure signs
- Misfire
- Rough idle
- Hard starting
- Poor acceleration
- Flashing check engine light
Maintenance notes
- Replace at the interval specified for the engine.
- Use the correct plug type and gap.
- Inspect old plugs for oil, coolant, or lean/rich clues.