Which other parts do owners name in the same complaint?

Among the 932 owner complaints naming this part, spark plug is named in 68% of them, more than any other part.

Spark plug68%

Head gasket9%

Fuel injector8%

Catalytic converter4%

Engine overhaul4%

Exhaust pipe3%

Owners name the spark plug most often in the same complaint, which is not proof that one caused the other. Ask the shop whether it checked the spark plug too, so you are not quoted twice for one visit.

Source: NHTSA owner complaint files · file downloaded 2026-10-05