Engine and gearbox (P)
P0455: EVAP system large leak detected
The evaporative emissions system has detected a large leak, which can allow fuel vapours to escape into the atmosphere. This can affect emissions and fuel efficiency.
Checked by a licensed car technician · last reviewed 29 September 2026
Symptoms
- Check engine light on
- Fuel smell near vehicle
- Decreased fuel efficiency
Common causes
- Fuel cap missing or loose
- Disconnected or damaged EVAP hose
- Faulty vent valve
- Cracked or damaged fuel tank
How to check it yourself
- Ensure fuel cap is properly tightened
- Inspect EVAP hoses for disconnections or damage
- Check vent valve for proper operation
- Inspect fuel tank for cracks or damage
Can I keep driving?
The car can still be driven, but it is advisable to fix the issue to prevent increased emissions and fuel loss.
General guidance, not a professional inspection. Confirm faults with measurements before buying parts, and use a qualified mechanic for brakes, steering, fuel leaks, airbags, and other safety-critical work. Terms and disclaimer