P0455 Hyundai Elantra
EVAP System Leak Detected (Gross Leak) · Powertrain Code · Medium · Repair: Easy
What is P0455?
A large leak has been detected in the EVAP system. Check gas cap first — if secure, look for disconnected or cracked EVAP hoses, a stuck-open purge valve, or a leaking charcoal canister.
When the Hyundai Elantra triggers code P0455 (evap system leak detected (gross leak)), it typically points to an issue in the powertrain system. Below you'll find the most common causes, symptoms, and repair options specific to the Hyundai Elantra.
This repair is rated easy, meaning basic tools, no lift needed.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your Hyundai Elantra.
Common Causes on Hyundai Elantra
- Gas cap missing or not sealing at all
- EVAP purge valve stuck wide open
- Large EVAP vapor line disconnect or crack
- Fuel filler neck seal completely failed
- Charcoal canister vent valve stuck open
Symptoms
- Check engine light illuminated
- Noticeable fuel smell near vehicle
- Gas cap warning light on dashboard
- Failed emissions test
- Fuel economy noticeably decreased
Notes for Hyundai Elantra
Elantra, Sonata, Forte, and K5 P0455 codes are most commonly caused by stuck-open purge valves or gas cap issues.