P0456 Subaru Forester
EVAP System Leak Detected (Very Small Leak) · Powertrain Code · Low · Repair: Easy
What is P0456?
A very small leak has been detected in the EVAP system. Often caused by an aging gas cap seal, hairline crack in an EVAP hose, or minor seal degradation.
When the Subaru Forester triggers code P0456 (evap system leak detected (very small leak)), it typically points to an issue in the powertrain system. Below you'll find the most common causes, symptoms, and repair options specific to the Subaru Forester.
This repair is rated easy, meaning basic tools, no lift needed.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your Subaru Forester.
Common Causes on Subaru Forester
- Deteriorated fuel cap O-ring
- Hairline crack in EVAP hose or fitting
- Minor leak at fuel filler pipe seal
- Charcoal canister micro-crack
Symptoms
- Check Engine Light on
- No driveability symptoms
- Possible faint fuel odor
Notes for Subaru Forester
P0456 is a small leak code; try a new OE fuel cap first, as this resolves the majority of cases on Subaru.