P0455 - EVAP System Leak Detected - Large Leak
P0455 is a generic powertrain diagnostic trouble code indicating EVAP System Leak Detected - Large Leak. It relates to the Auxiliary Emission Controls system.
DTC Breakdown (SAE J2012)
| System | Powertrain (P) |
| Type | Generic |
| Subsystem | Auxiliary Emission Controls |
| Fault Index | 55 |
| Standard | SAE J2012 / ISO 15031-6 |
What does diagnostic code P0455 mean?
The EVAP system has detected a gross (large) fuel vapor leak, indicating a major opening in the sealed evaporative emissions loop.
Severity Level & Driveability Details
Severity: Low to Moderate
It won't affect engine operation, but raw fuel vapors are escaping, which is bad for the environment.
Common Symptoms of P0455
- Check engine light illuminated due to a gross EVAP leak.
- Check gas cap light on the dashboard.
- Distinct fuel vapor odor.
Typical Causes for P0455
- Gas cap completely loose, missing, or damaged.
- Disconnected or large crack in EVAP lines.
- Failed vent valve stuck open.
- Cracked carbon canister.
Diagnostic and Troubleshooting Steps
Inspect the gas cap first. Inspect EVAP purge and vent lines. Perform a smoke test of the EVAP system to locate the leak.
Typical Repairs and Fixes
- Securing or replacing the gas cap.
- Replacing broken EVAP hoses.
- Replacing the vent valve or canister.
Sensor Location & Parts Involved
The EVAP canister and vent valve are located underneath the vehicle near the fuel tank; the purge valve is in the engine bay.
Clearing Code & Recurrence
Clear the code with a scan tool to reset the monitors and perform a verification drive.
Emissions & Smog Inspection Impact
Allows raw fuel vapors (hydrocarbons) to vent into the atmosphere, causing smog check failures.
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Related Diagnostic Codes
Sources & References
This diagnostic guide is compiled and verified against the following authority sources:
- EPA EVAP Standards
- CARB OBD II regulations
Frequently Asked Questions about P0455
What does the EVAP control system gross leak code P0455 mean?
The Evaporative Emission Control (EVAP) system logged P0455 after detecting a gross leak in the sealed fuel vapor loop.
Is it safe to drive with the EVAP control system gross leak code P0455 active?
Yes, an EVAP fault poses no danger to vehicle function.
How much does it cost to repair a EVAP control system gross leak code P0455 fault?
A new gas cap is $15-$30, while vent or purge solenoids run $150-$300 and carbon canisters cost $300-$500.
What are the common causes of the EVAP control system gross leak code P0455?
Trigger conditions for the EVAP control system gross leak code P0455 include: Loose, dirty, or cracked gas cap seal., Hairline cracks in the EVAP canister or vacuum lines., Failed EVAP vent control valve or purge valve..
Can I clear the check engine light for EVAP control system gross leak code P0455?
Clear the code with a scan tool to reset the monitors and perform a verification drive.
Will the EVAP control system gross leak code P0455 cause an inspection failure?
Allows raw fuel vapors (hydrocarbons) to vent into the atmosphere, causing smog check failures.