TorqueMech OBD Code Guide
P0455 - Evaporative Emission Control System Leak Detected (Gross Leak)
Large EVAP leak detected.
Severity
Low
Drivability
Usually no drivability issue, fuel vapor leak likely
Typical Cost
$20 - $450+
Code Meaning
Large EVAP leak detected.
What You May Notice
- Check engine light with little or no drivability change
- Stronger fuel smell than a small EVAP leak
- EVAP monitor not ready for emissions testing
- Loose or missing gas cap is common
Common Causes
Gas cap off
Disconnected/ruptured EVAP hose
Failed vent valve
Quick Checks
- Check gas cap is present/tight
- Inspect EVAP hoses for disconnection
- Smoke test / check vent valve
EVAP Purge / Vent Checks
- Verify gas cap seal and filler neck condition first
- Smoke test lines from canister to engine bay
- Command purge and vent valves with a scan tool if available
- Inspect vent valve wiring and connectors for corrosion or damage
Likely Repairs
Use test results to confirm the fault before pricing the repair.
EVAP system diagnosis
Estimator-ready next step for a confirmed repair path.
EVAP leak smoke test
Estimator-ready next step for a confirmed repair path.
Gas cap replacement
Estimator-ready next step for a confirmed repair path.
EVAP vent valve replacement
Estimator-ready next step for a confirmed repair path.
Next Steps
Move from the code to a diagnosis path, then into repair pricing once the fault is confirmed.