obdII code p0446 comes up. can you tell me troubleshooting procedure ?

you need a scan tool to verify the pcm can turn the solenoids on and off. you need to ohm out the solenoids to verify they are ok. you need to do a smoke test to look for leaks. Roy

Roy is right evap component tests are the hardest to do and need a scan tool test procedures and smoke machine. Not every scan tool can verify the repairs are done correctly and it requires proper drive cycles with specific parameters to be met before the computer in your car tests the system itself and verifies all is OK.

you can firstly try to check and repair vent valve, control circuit and power circuit (if has any open,short, or resistance problem), and PCM and need a scan tool to verify if it's repaired greetings