2002 Toyota Corolla PO441 and PO446

All canister to valve hoses at canister are ok, some rust on VSV casing (northern car) hole in tube feeding from service port (replaced) waiting to see if code returns. Just adding info to a prior post on this same subject. Since there are 4 valves at the canister a switch and the switch near the service port, who's to know which is bad if the hole in the feed tube does not fix these DTC codes. Customer replaced his gas cap 4 times before I saw this car. Any info/diagnostics would be great beyond the layman posts i see, thanks.

edit: forum doesn't post subject being: Codes PO441 and 446