Flashing vs Steady Check Engine Light
A steady light is a stored fault; a flashing light is an urgent misfire warning that can destroy the catalytic converter.
Steady check engine light
The computer has stored one or more faults. You can usually drive carefully to complete a diagnosis, but do not ignore it for weeks. Common causes include gas cap, O2 sensors, catalyst efficiency, and lean conditions.
Flashing check engine light
Severe misfire is occurring right now. Raw fuel can overheat and melt the catalytic converter. Reduce throttle, avoid high RPM, and scan for P0300–P0308 codes as soon as possible.
Both lights or other warnings
If the oil pressure, temperature, or red brake lights are also on, treat those as higher priority than the CEL.
Related Fault Codes
Related Symptoms
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