I am getting a p0441 engine code. on 1996 Toyota Avalon

Everything I find tells me this is the vapor canister causing the issue. However, it says this when code is present with p0446. I only have 1 code. What other possibilities could it be when the only code is p0441?

Asked by for the 1996 Toyota Avalon
could be anything to due the evap system. have a diag with a smoke test to determine prob
1 more answer
3 different compotent failures can cause that code and also the vacume lines that work that system can cause it. Charcoal Canister, Purge Vacuum Switching Valve, Three Way Vacuum Switching Valve