Solving P0455 on Your 2023 Toyota Highlander
A P0455 on your 2023 Toyota Highlander means the ECM detected a large EVAP system leak. Your 4th-generation Highlander—now with the 2.4L turbocharged engine or Hybrid powertrain—is under warranty for this repair. Check the gas cap first.
Symptoms
- Check engine light with P0455
- Possible faint fuel odor
- Gas cap not clicking properly
- EVAP readiness monitor incomplete
Top Causes
- Gas Cap Seal (Very High Likelihood): Loose or defective. Tighten until it clicks. Warranty-covered.
- Canister Close Valve (CCV) (Medium Likelihood): Toyota's vent valve stuck open. Warranty-covered.
- EVAP Hose Connection (Medium Likelihood): Factory assembly issue. Warranty-covered.
- Purge VSV (Low Likelihood): Vacuum switching valve. Warranty-covered.
- ECU Software Calibration (Low Likelihood): Updated EVAP monitoring. Free reflash.
What to Do
Tighten the gas cap and drive 2–3 days. If the light persists, your Toyota dealer will use Techstream diagnostics—all free under warranty.
Warranty Coverage
Your 2023 Highlander is covered by Toyota's 3-year/36,000-mile basic warranty (through 2026), 5-year/60,000-mile powertrain warranty, and federal emissions warranty (8yr/80k). All EVAP repairs are free.
Safe to Drive?
Yes. P0455 doesn't affect the Highlander's 2.4T engine, Hybrid system, AWD, or towing capability.