P0446 Chevrolet -

Question

Possible fixes for the code PO446 truck has new evac canister and new solenoid and check light still is on.

Answer 1

P0446 Evaporative emission control system Vent control circuit malfunction

What usually set this code , is the FTP (Fuel tank pressure) sensor. What happens is the FTP does not report the correct pressure in the fuel tank and the ECM see this as a vent control problem. The FTP does not survive long in its working enviroment and this is one of the reason it fails to report the right condition.