EVAP System Troubleshooting Mastering P0446 for Peak Performance

P0401 is usually the EGR VSV. P0446 can be a number of things including vapor leaks. I start with the gas cap (quick/easy). Sometimes it is the ... Evaporative Emission System Malfunction P0446: Evaporative Emission Control System Ventilation Control Circuit Malfunction - Auto 24 cards ... Problems/Service/Repairs - PO446 Error Code - I know that this code is an emissions venting problem that can be associated with the gas cap, ... i find this odd since i replaced the vent valve AND filter with brand new items. i also parts cannoned a new gas cap, canister, and purge ... The code P0446 is set when the engine computer recognizes a fault or restriction at the vent control part of the Evaporative emission control system (EVAP). The Purge Valve is till working, but it seems the canister isn't venting and my hoses are good. I left the cap slightly lose so it could vent, The truck seemed ... Well-Known Member. Established Member. Joined: Mar 11, 2007. Messages: 7,580. Location: poteet,texas. po446 start HX65 2003 PCED OBD SECTION 5 ... That code is not common in gen9 and is usually caused one of these ways: 1) malfunctioning Evaporative Emission Canister Vent Solenoid Valve or pinched vent ... If you drive in a dusty/dirty enviroment, the EVAP canister vent valve can become blocked with dirt and crud. ... and a new bracet for the valve, ... A PO446 is a evap code haveig to do with the canister path being blocked or restricted ,and a purge selenoid valve is often time the culprit.