P0455
Low SeverityEVAP System Large Leak Detected
EVAP System
What Does P0455 Mean?
A significant leak in the EVAP system. Often a loose gas cap or a disconnected hose.
Common Fix
Replace gas cap or fix disconnected hose
Estimated Cost (DIY)
$5 - $50
Symptoms
- ⚠️Check engine light
- ⚠️Possible fuel smell
- ⚠️Failed emissions
Common Causes
Loose or missing gas caplikely
Disconnected EVAP hosepossible
Cracked canister or hosepossible
Failed purge or vent valve stuck openpossible
How to Diagnose P0455
- 1Check gas cap — tighten or replace
- 2Visual inspection of all EVAP hoses
- 3Smoke test EVAP system if cap is OK
- 4Check purge and vent valve operation
Need to read or clear this code?
Shop OBD2 Scanners on Amazon →Frequently Asked Questions
- Is P0455 the gas cap code?
- Most often yes. A loose, cracked, or missing gas cap is the #1 cause of P0455.
- How long after tightening the cap does the code clear?
- The code clears after 2-3 drive cycles (cold start, warm up, highway driving) if the leak is fixed.