Check Engine Code
P0455
Evaporative Emission Control System Leak Detected (Large Leak)
Severity: low
DIY difficulty: 1/5
Typical cost: $0–$400
What P0455 means
Large-leak version of P0442. Often set immediately after refueling if the gas cap was left loose or not turned until it clicks.
Symptoms
- Check engine light
- Fuel smell around the car (occasional)
Likely causes (most common first)
- Gas cap completely off or loose
- Large hose disconnected or cracked
- Failed purge valve stuck open
- Big crack in the filler neck
Can I keep driving?
Low — mostly emissions/economy
Typical repair cost
DIY fixes can start near $0 (parts only). Shop repairs for P0455 typically run up to $400 depending on the underlying cause and vehicle. Start with the most common cause — Gas cap completely off or loose — before throwing parts at it.
Related codes
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