P0457: Evaporative Emission System Leak Detected (Fuel Cap Loose/Off)
The system detected a large leak right after fueling and suspects the gas cap.
Green, yellow, red: three ways P0457 can look
The same code can be a quick fix or a reason to pull over. Match your situation to the closest example.
Keep an eye on it
Cap was loose. Tighten it; the light clears after some driving.
Schedule a repair
Cap is tight and it comes back. Replace the cap, then test.
Stop and get help
Fuel smell or leak. Don't drive.
Symptoms you might notice
- Usually none
Common causes, cheapest first
- Gas cap loose or off
- Worn cap seal
- Filler neck damage
What you can check before calling
- Tighten the cap until it clicks
A code points to a system, not a part. Replacing parts based on the code alone is how people spend money without fixing the problem. Testing confirms the cause first.
Want the full story? Read our guide: Check engine light after getting gas? Gas caps and EVAP codes.
Generic codes (second character 0) mean the same thing on every vehicle. Some manufacturers add their own details, so check service information for your exact vehicle.
More evap (fuel vapor) codes
- P0440
Evaporative Emission System Malfunction - P0441
Evaporative Emission System Incorrect Purge Flow - P0442
Evaporative Emission System Leak Detected (Small Leak) - P0446
Evaporative Emission System Vent Control Circuit Malfunction - P0449
Evaporative Emission System Vent Valve/Solenoid Circuit Malfunction - P0456
Evaporative Emission System Leak Detected (Very Small Leak)
Look up another code
Cummins fault code (like 1922), J1939 SPN and FMI (like SPN 3251 FMI 0), or an OBD-II code (like P0420).
Questions
What does P0457 mean?
P0457 means "Evaporative Emission System Leak Detected (Fuel Cap Loose/Off)". The system detected a large leak right after fueling and suspects the gas cap.
Can I drive with code P0457?
It depends on what the vehicle is doing. Green: Cap was loose. Tighten it; the light clears after some driving. Yellow: Cap is tight and it comes back. Replace the cap, then test. Red: Fuel smell or leak. Don't drive.
What causes P0457?
The most common causes are: gas cap loose or off; worn cap seal; filler neck damage.
Is P0457 a serious code?
It can be. Fuel smell or leak. Don't drive.
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