P0455 Ford Bronco
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 Ford Bronco 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 Ford Bronco.
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 Ford Bronco.
Common Causes on Ford Bronco
- Gas cap missing or damaged from off-road conditions
- EVAP canister vent valve stuck open from debris intrusion
- EVAP vapor line completely severed from undercarriage impact
- Charcoal canister cracked or water-filled from trail use
- Fuel tank vapor connection pulled apart from chassis flex
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 Ford Bronco
Bronco off-road use can cause severe EVAP damage. After water fording, the charcoal canister may need replacement from water contamination.