Car Runs Rough
A rough idle, hesitation, or shaking under power usually means one or more cylinders are not firing cleanly.
Should you keep driving?
A steady misfire dumps raw fuel into the exhaust and can damage the catalytic converter. Get it looked at soon.
Common causes
Worn spark plugs or coilsThe most common cause of a misfire, especially past 60–100k miles.
Vacuum leakUnmetered air upsets the fuel mixture and causes a rough, high idle.
Dirty fuel injectors or filterRestricted fuel delivery makes the engine stumble under load.
Failing sensorsA bad mass-airflow or oxygen sensor can throw the mixture off.
Rather have a pro handle it? Find a vetted local mechanic.