Dave, I think that may be wrong. You linked to the PURGE valve, which does sit where you say it does. But P0446 implies (to me anyway, could be wrong) the VENT VALVE. That is, the shutoff/vent valve on the Charcoal Caninster. See the snips from the Student Guide below.

And Im not so much correcting you as ASKING you - I've been trying to help Andy (Aking57) with his P0446 code, they changed the vavle you point out, CEL came back next trip.