Diagnostic Trouble Code
P0456 — EVAP Emission Control System Leak Detected (Very Small)
EVAP Emission Control System Leak Detected (Very Small)
Definition
A very small leak (less than 0.020" diameter) has been detected in the EVAP system. These micro-leaks are the hardest to find and often require smoke testing equipment.
Common Causes
- Slightly loose gas cap or worn cap seal
- Micro-crack in EVAP hose or fitting
- Aging O-ring on fuel sender unit
- Vent valve or purge valve with minor seepage