Took my 2004 Rav4 in to have trouble code evaluated. Codes came back as:

P0441 - Evap Incoorect Purge Flow
P0442 - EVAP Small Leak detected
P0446 - EVAP Vent Fault
P0455 - Evap large Leak

Notes are as follows:
Purge operates as designed as well as the Canister Closed Valve. Vacuum Swithcing Valve is not holding vacuum and released when energized. Smoked the system and found that the Vent Valve is not sealing properly. At this time we recommend replacing the Charcoal Canister because the vent is located inside the canister.

I don't know exactly which vent/valve they're talking about. When I search for vent valves, I just get purge solenoids. I don't doubt the shop, I'm just going to replace the parts myself and don't want to spend more than I have to. I've just never had to replace a whole canister before; is the aforementioned vent is a part of the canister rather than an attachment like a solenoid? Thanks in advance.