Following the P0446 Evidence on Your 2019 Subaru Forester
A P0446 code on your 2019 Subaru Forester points to an EVAP vent control circuit malfunction. As the first model year of the fifth-generation Forester (SK platform), your compact SUV's 2.5L FB25 boxer engine uses a canister vent control valve to manage evaporative emissions. After six years of service, electrical wear in this circuit has the PCM's attention.
The SK Forester debuted on the Subaru Global Platform, bringing improved structure and dynamics. The EVAP system follows Subaru's established boxer-engine design with the vent valve near the charcoal canister.
Symptoms You May Have Noticed
- Check engine light on with P0446
- Fuel nozzle clicking off repeatedly at the pump
- EVAP readiness monitor not setting
- Faint fuel vapor smell
- May be accompanied by P0441 or P0455
Top Suspects
- Canister Vent Control Valve Failure (High Likelihood): Six years of use wears down the vent valve solenoid. Coil degradation and mechanically stuck valves are common at this age. Parts $40–$90, labor $80–$180.
- Wiring and Connector Corrosion (High Likelihood): Years of road salt and moisture corrode the vent valve's electrical connections. Subaru Foresters often live in snowy climates, accelerating this wear. Repair costs $75–$255.
- Charcoal Canister Degradation (Medium Likelihood): Six years of fuel vapor absorption breaks down the activated charcoal. Canister replacement costs $140–$310.
- Purge Control Solenoid Issue (Medium Likelihood): The boxer engine's purge solenoid can affect EVAP system operation when it begins to fail. Replacement costs $70–$185.
- Gas Cap Seal Failure (Low Likelihood): A simple and inexpensive first check. A worn seal can sometimes affect vent circuit diagnostics. New cap costs $12–$30.
DIY Diagnostic Approach
- Replace the gas cap first ($12–$30) — quick win if that's the issue
- Scan for codes and note freeze frame conditions
- Locate the vent control valve near the charcoal canister
- Inspect the connector for corrosion — clean or replace as needed
- Test vent valve resistance with a multimeter
- Apply 12V to confirm mechanical operation
- Trace wiring from the valve to the PCM for damage
Cost Estimates
- Vent control valve: $120–$270
- Wiring/connector repair: $75–$255
- Charcoal canister: $140–$310
- Purge solenoid: $70–$185
- Gas cap: $12–$30
- Diagnostic fee: $70–$125
Can I Drive With P0446?
Yes. P0446 is an emissions circuit code with no effect on your Forester's boxer engine, CVT, Symmetrical AWD, or X-MODE. The vehicle drives normally in all conditions.
Warranty and DIY
Your 2019 Forester is past Subaru's 3-year/36,000-mile basic warranty, but the federal emissions warranty covers EVAP components for 8 years/80,000 miles — potentially through 2027. Check your mileage. If past warranty, the vent valve is a solid DIY project. The Subaru community has detailed repair guides for the SK platform.