P0456 on Your 2024 Outback: Investigating the Trail
Your 2024 Outback (6th generation) has flagged P0456—a very small EVAP leak at the 0.020-inch threshold. The 2.5L Boxer four-cylinder (or 2.4L turbo XT) with standard Symmetrical AWD uses a traditional EVAP system. Subaru has a history of EVAP-related TSBs. Fully covered under Subaru's 3yr/36k warranty through 2027.
Clues
- Check engine light on
- P0456 stored
- No drivability symptoms
- Gas cap may not be fully tightened
Suspects
- Gas Cap Seal (High Likelihood): Traditional threaded cap. $0 warranty.
- Purge Control Solenoid Valve (High Likelihood): Subaru has TSBs for purge valve failures. $0 warranty.
- Canister Vent Valve (Medium Likelihood): Standard vent control. $0 warranty.
- EVAP Line (Low Likelihood): Under-body routing on the unibody platform. $0 warranty.
- Software Calibration (Low Likelihood): Detection sensitivity. $0 warranty update.
What to Do
- Reseat gas cap—tighten until it clicks
- If light persists, dealer appointment—covered under 3yr/36k through 2027
- Ask about EVAP-related TSBs—Subaru has issued several
Cost
- Under warranty: $0
- 3yr/36k through 2027
- Federal emissions through 2032
Can I Drive?
Yes. P0456 has zero impact on the Boxer engine, AWD, EyeSight, or X-MODE.
Warranty
Subaru's 3yr/36k through 2027. 5yr/60k powertrain. Federal emissions 8yr/80k through 2032. EVAP falls under emissions—long coverage.