Key statistics. Approximately 37% of cars fail their MOT on the first attempt in the UK. (Car Owl (based on DVSA data), 2026). Over 11 million of the more than 30 million MOT tests conducted annually in the UK result in a fail. (Car Owl (based on DVSA data), 2026).
A flashing check engine light means there's a severe problem with your car's engine, typically a misfire, that could cause significant and irreversible damage to critical components like the catalytic converter very quickly. It's an urgent warning that requires immediate attention and you should stop driving as soon as safely possible.
What's the Difference Between a Solid and Flashing Check Engine Light?
The key difference between a solid and a flashing check engine light lies in the urgency and severity of the underlying issue. A solid, illuminated check engine light indicates a problem that requires attention soon, but usually isn't an immediate emergency, like a loose fuel cap or a minor sensor fault. However, a flashing check engine light signals a critical
Frequently Asked Questions
Can I still drive if my check engine light is flashing?
No, a flashing check engine light indicates a serious problem, often an engine misfire, which can cause severe damage to your catalytic converter or engine if you continue to drive. You should pull over safely and seek recovery immediately.
What are common causes of a flashing check engine light?
The most common cause of a flashing check engine light is an engine misfire. Other serious issues can include faulty ignition coils or spark plugs, fuel system problems, catalytic converter damage, or severe vacuum leaks.
Will a flashing check engine light cause my car to fail its MOT?
Yes, an illuminated engine management light (which includes a flashing one) is considered a major fault and will result in an automatic MOT failure for most modern vehicles in the UK.
