P0455 Mazda Cx-5
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 Mazda Cx-5 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 Mazda Cx-5.
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 Mazda Cx-5.
Common Causes on Mazda Cx-5
- Gas cap missing or not sealing
- EVAP purge solenoid stuck wide open
- Large EVAP vapor line disconnection
- Charcoal canister vent valve stuck open
- Fuel filler neck gasket complete failure
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 Mazda Cx-5
CX-5, CX-50, Mazda3, and CX-30 P0455 codes are almost always a gas cap or stuck-open solenoid. Reliable EVAP systems overall.