Why is my check engine light flashing?

A flashing check engine light is not the same as a solid one — it means an active misfire severe enough to dump unburned fuel into the catalytic converter, where it will literally melt the cat if you keep driving. Pull over as soon as it's safe, get the car towed, and have it scanned. Common causes: failed ignition coil, fouled spark plug, bad fuel injector. Driving on a flashing CEL can turn a $200 coil into a $2,000 catalytic converter.

Get a free AI-ranked diagnosis for your exact year, make and model — with fair repair cost ranges and DIY-vs-shop guidance.