Loose, missing or faulty fuel filler cap; Disconnected or cracked EVAP hoses; Faulty purge valve or canister vent valve; Damaged charcoal canister; Faulty leak detection pump or pressure sensor.

Evaporative emissions (EVAP)

P0455 Evaporative Emission (EVAP) System Leak Detected (Large Leak)

The EVAP system stores fuel vapour from the tank in a charcoal canister and later purges it into the engine. The ECU runs a leak test by sealing the system and checking pressure or vacuum, and sets P0455 when it detects a large leak or no flow.

Common causes

Loose, missing or faulty fuel filler cap
Disconnected or cracked EVAP hoses
Faulty purge valve or canister vent valve
Damaged charcoal canister
Faulty leak detection pump or pressure sensor

Typical symptoms

Check engine light (MIL) on
Possible fuel vapour smell
Emissions test failure
Usually no change in drivability

P0455 and NuoVolta

If the EVAP system has been removed or modified for off-road or motorsport use, where permitted by law, the NuoVolta EVAP Removal solution adjusts the ECU calibration and the DTC removal feature can disable this code. Check the fuel cap and hoses first, as they are the most common causes.

EVAP Removal Available for 69 ECUs

Diagnose and repair real faults first. Removing or disabling emission systems is only permitted where allowed by law, for example for off-road or motorsport use.