Tracking Down P0440 on Your 2024 Subaru WRX
Your 2024 Subaru WRX has flagged a P0440 code — an EVAP system malfunction. The WRX (VB platform) features a 2.4L turbo Boxer four-cylinder (271 hp) with either a 6-speed manual or SPT CVT and standard Symmetrical AWD. As a relatively new performance vehicle, P0440 should be straightforward to resolve. Let's gather the evidence.
Symptoms to Watch For
- Check engine light illuminated
- Faint gasoline odor
- Slight fuel economy decrease
- Fuel nozzle clicking off early
- Failed emissions inspection
Your WRX drives perfectly normally. Full boost, power, and AWD performance are completely unaffected.
Top Suspects: Ranked by Likelihood
- Gas Cap Not Fully Seated — Check first. Estimated repair: $0–$25.
- Purge Control Valve Defect — Manufacturing defect or early failure on the 2.4L turbo. Estimated repair: $80–$210 (warranty-covered).
- Vent Control Valve Issue — Early failure near the charcoal canister. Estimated repair: $85–$225 (warranty-covered).
- Loose EVAP Connection — Factory fitting not fully secured. Estimated repair: $0–$85 (warranty).
- Aftermarket Modification Effects — If modified, check EVAP routing. Estimated repair: varies (may void warranty).
Diagnostic Steps
- Check gas cap — remove, inspect, reinstall firmly
- Clear code, drive 50+ miles, monitor
- If stock, schedule Subaru dealer appointment
- If modified, verify all EVAP connections are intact
- Check for TSBs on the 2024 WRX
Repair Cost Breakdown
- Gas cap: $0–$25
- Purge control valve: $80–$210 (warranty if stock)
- Vent control valve: $85–$225 (warranty if stock)
- EVAP connection: $0–$85 (warranty)
Warranty: Your 2024 WRX is covered by Subaru's 3-year/36,000-mile basic warranty — provided no modifications affect the EVAP system.
Can I Drive With P0440?
Yes. P0440 is emissions-only. Full boost, power, and performance are available.
DIY or Dealer?
If stock, dealer — warranty covers the repair. If modified, DIY may be preferred to avoid warranty scrutiny. Check your EVAP connections first.