P0455 on Your 2023 Subaru Legacy
A P0455 on your 2023 Legacy means the ECM found a large EVAP leak. Your 7th-generation Legacy with the 2.5L boxer (or 2.4L turbo) is likely under warranty. The gas cap is the first place to investigate.
Symptoms
- Check engine light on
- P0455 code stored
- Possible fuel odor
- Gas cap issue
Top Causes
- Gas Cap Seal (Very High Likelihood): Loose or defective. Check warranty.
- Purge Control Solenoid (Medium Likelihood): Valve malfunction. Likely warranty-covered.
- Vent Control Valve (Medium Likelihood): Testing failure. Likely warranty-covered.
- Vapor Line (Low Likelihood): Connection issue. Warranty-covered.
- Charcoal Canister (Low Likelihood): Rare on newer vehicles. Warranty-covered.
What to Do
Tighten the gas cap and drive 2–3 days. If P0455 returns, visit your Subaru dealer. Check warranty status—most 2023 models are still covered.
Warranty
Your 2023 Legacy should be under Subaru's 3-year/36,000-mile warranty through 2026. Federal emissions warranty (8yr/80k) covers EVAP through 2031.
Safe to Drive?
Yes. P0455 is a vapor code. The boxer engine, CVT, Symmetrical AWD, and EyeSight all work normally.