TROUBLESHOOTING

Check Engine Light On or Flashing? What to Do

A check engine light means the car's computer has detected a problem. A steady light is less urgent than a flashing one, but both are worth reading the code for, since some causes are cheap and others can damage the engine or exhaust system if ignored.

A flashing check engine light usually means an active engine misfire. Reduce speed, avoid hard acceleration, and have the car checked soon, because continued driving can damage the catalytic converter.

Quick checks you can do safely

Tighten the gas cap until it clicks. A loose or damaged cap is a common and cheap cause of the light.
Notice whether the car drives differently, such as rough idling, hesitation, or loss of power.
Check whether any other warning light comes on with it, like oil pressure or temperature.

What's usually behind it

A loose or damaged gas cap
A failing oxygen or mass airflow sensor
Worn spark plugs or a failing ignition coil causing misfires
An emissions component problem

Still not sure? Let us take a look.

These checks can point you in the right direction, but a proper diagnosis needs the right equipment. We'll find the actual cause and explain it before recommending any work.

QUESTIONS

Check Engine Light On or Flashing: common questions

Can I clear the code myself?

You can, but the light usually comes back if the underlying problem is still there. Finding the actual cause is what fixes it.

Is the code scan really free?

Yes. We read the code for free, so you know what you're dealing with before you pay for any repair.

This guide is general information, not a diagnosis. Every vehicle is different, and our technicians will confirm the cause before recommending repairs. Serving Mission Viejo, Rancho Santa Margarita, Laguna Hills and nearby communities.