Check Engine Light Flashing After Getting Gas: Misfire Warning or EVAP Vapor Flooding?

When the MIL starts flashing only after a fill-up, do not stop at the word misfire. The flashing light still means catalyst risk, but the refuel timing raises purge-flow and vapor-flooding faults much higher than it would on an ordinary coil or plug failure.

Likely related codes

Start your diagnostic path here

P0300 — Random/Multiple Cylinder Misfire Detected P0172 — System Too Rich (Bank 1) P0420 — Catalyst System Efficiency Below Threshold (Bank 1) P0441 — Evaporative Emission Control System Incorrect Purge Flow P0496 — Evaporative Emission System High Purge Flow P0451 — Evaporative Emission Control System Pressure Sensor Range/Performance

Connected paths

Guides to read next

Browse all guides

Built to keep related fixes, symptoms, and hubs one step away.

How to Diagnose an Engine Misfire Step by Step How to Test an EVAP Purge Valve Without Guessing Can You Drive With a Flashing Check Engine Light?Bad Gas vs EVAP Purge Problem: How to Tell Which One You Actually Have Refuel Misfire vs Ignition Misfire: How to Tell Which One You Actually Have