What P0455 Means
Same EVAP system as P0442, but the leak detected is large enough that it's easier to find — often a completely missing or open component rather than a small crack.
Common Causes
- Missing, loose, or damaged fuel cap
- Disconnected or badly cracked EVAP hose
- Faulty purge or vent valve stuck open
Symptoms You Might Notice
- Usually no drivability symptoms
- Check engine light on
- Possible fuel smell near the tank or engine bay
What to Check First
- 1
Check that the fuel cap is present, undamaged, and properly tightened
- 2
Visually trace EVAP hoses from the tank to the engine for anything disconnected or badly cracked
- 3
A smoke test will quickly show a large leak, since it's more obvious than for P0442