P0457 - EVAP System Leak Detected (Fuel Cap Loose/Off)

The Technical Definition: The PCM detected a large leak in the EVAP system, which is often caused by a loose or missing fuel cap.

Common Symptoms: Symptoms include an illuminated check engine light and the smell of fuel.

Typical Fix: Tighten the gas cap, clear the code with a scanner, and see if it returns. You may need to replace the gas cap if it is damaged or fails to form a good seal.