P0456
EVAP System Leak Detected (very small leak)
Powertrain · Generic (all makes)System: Emissions
Safe to drive short term. Book a repair.
Likely causes
- Gas cap seal
- Pinhole in an EVAP hose
- Purge valve leaking slightly
What to check first
A very small EVAP leak. A smoke test is the reliable way to find it.
Typical repair cost
$50 – $450
Independent-shop parts and labor for the usual fix. Your price depends on the actual cause and the vehicle.
Next step
General information, not a diagnosis of your vehicle. Repair costs are typical shop ranges, not quotes.