Cracking the P0440 Case on Your 2022 Subaru Impreza
A P0440 code on your 2022 Subaru Impreza points to an EVAP system malfunction. The fifth-generation Impreza (GT platform) features a 2.0L Boxer four-cylinder (152 hp) with Lineartronic CVT and standard Symmetrical AWD. With a few years of service, certain EVAP components may be ready for attention. Let's trace the evidence.
Symptoms
- Check engine light on
- Faint gasoline odor
- Slight MPG decrease
- Fueling difficulties at the pump
- Emissions test failure
Your Impreza drives normally. The Boxer engine, CVT, and AWD are unaffected.
Most Likely Causes
- Gas Cap — Worn seal or loose. Check first. Estimated repair: $5–$25.
- Purge Control Valve — The purge solenoid on the 2.0L Boxer can develop sticking issues. Estimated repair: $70–$185.
- Vent Control Valve — Controls EVAP system airflow near the charcoal canister. Estimated repair: $75–$205.
- Vapor Line Leak — Small cracks from heat cycling in the compact engine bay. Estimated repair: $40–$125.
- Fuel Tank Pressure Sensor — Can provide inaccurate readings. Estimated repair: $80–$220.
Diagnostic Steps
- Replace gas cap, clear code, drive 50+ miles
- Scan for companion EVAP codes
- Test purge and vent valves with scan tool
- Perform EVAP smoke test
- Check for Subaru TSBs on the 2022 Impreza
Repair Costs
- Gas cap: $5–$25
- Purge control valve: $70–$185
- Vent control valve: $75–$205
- Vapor line: $40–$125
- FTP sensor: $80–$220
- Diagnostic: $80–$150
Warranty: Subaru's 3-year/36,000-mile basic warranty has likely expired. Check your purchase date and mileage.
Can I Drive With P0440?
Yes. No drivability or safety concerns.
DIY Feasibility
Gas cap is trivial. The Boxer engine's flat layout makes the purge valve accessible on top. The vent valve underneath requires more effort but is doable with basic tools. The Impreza shares EVAP parts with the Crosstrek, so parts are widely available.