P0455 Code: EVAP System Leak Detected (Large Leak)
P0455 means the evaporative-emissions system has a large leak — a significant vapour escape.
- Applies to
- All OBD-II vehicles (any make or model)
- Est. repair cost
- $20 – $350
- Time to fix
- 1-3 hours
What it means
The most common cause is a missing/loose fuel cap; also a disconnected or split EVAP hose, or a stuck-open purge/vent valve. This is a generic OBD-II powertrain code defined in the SAE J2012 standard, so it applies to virtually any 1996-or-newer OBD-II vehicle — cars, trucks, and modern fuel-injected motorcycles — from any manufacturer (Toyota, Honda, Ford and the rest). Read it with any OBD-II scanner; the meaning is the same across brands, though the exact repair can vary by engine.
Symptoms
- Check engine light on
- Strong fuel smell possible
- No major drivability effect
How to fix it
- 1
Check the cap and hoses
1. Confirm the fuel cap is present and sealing. 2. Inspect EVAP hoses for splits or disconnections. 3. Smoke-test if needed, then clear the code.
Frequently asked questions
P0455 right after fuelling — why?
A cap left loose or not clicked tight after filling is the classic trigger for a large-leak code. Re-seat the cap and clear the code.
Last updated July 16, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.