The computer sees purge flow that does not match what it commanded. The driver may notice rough idle after refuelling or only the engine light.
Causes vary by car. Test before you order a part.
Likely causes, most common first
- Faulty purge valve
- Blocked or cracked purge hose
- Saturated charcoal canister
- Wiring fault at the valve
Parts usually involved
- Purge valve Find at suppliers
- EVAP hoses Find at suppliers
- Charcoal canister Find at suppliers
Test before you replace
Command the purge valve with a scan tool and check for vacuum at the hose and flow to the canister.
General guidance for generic OBD2 codes. Always follow the maker's procedure for the car in front of you.