P0457Powertrain
Powertrain · SAE
EVAP Leak Detected (Fuel Cap)
Meaning
The ECU detects a large EVAP system leak traceable to the fuel filler cap area. A loose or missing fuel cap is the most common cause of this code, allowing hydrocarbons to escape into the atmosphere.
Common causes
- Loose or improperly seated fuel cap (most common)
- Damaged cap O-ring or gasket
- Cracked filler neck
- Damaged EVAP hose at tank neck
Symptoms
- MIL illuminated (may take several drive cycles)
- Fuel odor near the fuel cap
- EVAP monitor fails
Severity
Low to moderate — no effect on driveability but generates hydrocarbon emissions and causes the EVAP monitor to fail.
What to do
- Remove and firmly re-seat the fuel cap until it clicks
- Inspect cap O-ring for damage or deformation
- Inspect filler neck for cracks
- Clear DTC and complete an EVAP drive cycle
- If fault returns, inspect hoses at the tank