Is it safe to drive with a flashing check engine light?
A flashing check engine light means the engine is actively misfiring badly enough to damage the catalytic converter. Drive only as far as you need to, gently, and get it checked as soon as you can. If the car is shaking hard, losing power or smells strongly of fuel, pull over and have it towed.
Why a flashing light is different
A steady light means a fault has been stored. A flashing light means something is happening right now: usually one or more cylinders aren't firing properly. The unburned fuel from that cylinder goes into the exhaust and burns inside the catalytic converter, which can overheat and melt its internal structure within a short drive.
What to do right now
- Ease off. Avoid hard acceleration, towing, steep hills and high speed.
- Check for other signs. Heavy shaking, a strong fuel smell, smoke or a loss of power mean you should stop and arrange a tow.
- Get it to a shop soon. The sooner the misfire is fixed, the less chance of collateral damage.
Common causes of misfires
- Worn spark plugs, especially past their replacement interval
- A failing ignition coil, often one cylinder at a time
- A clogged or leaking fuel injector
- A vacuum leak making the mixture too lean
- Low compression from a valve or head gasket problem (less common)
- Moisture in the coil wells after washing the engine or heavy rain
We find which cylinder is misfiring and why, then fix that, rather than replacing a full set of parts on a guess.
From drivers who came to us
They were very friendly and offered to check my vehicle out and check the engine with the codes… My car worked perfect after I left.
I found them to be honest, reliable and thorough with the work they did on my Honda Fit. They were able to diagnose a problem that other auto shops had been having issues finding.
Excerpts from verified customer reviews on Yelp.
More questions
How far can I drive with a flashing check engine light?
As little as possible. A few gentle miles to a shop is usually fine; a highway trip is not. Unburned fuel overheats the catalytic converter quickly.
Why does the light flash and then go steady?
Many cars flash only while a severe misfire is happening, such as under load or acceleration, and return to steady when it eases. It's still a misfire that needs attention.
Is a misfire a big repair?
It depends on the cause. A worn spark plug or ignition coil is a common, straightforward repair. Leaving it until the catalytic converter is damaged is what turns it into a big one.