I have had an engine light on my 2002 Toyota Solara for a month. I hooked up a scanner to it and got code 446. It appears to be a bad vacuum switching valve. If so, would this affect the running of the engine? Also, if it is a bad vsv, how much do they cost and who sells them?

If I were you I'd go for the whole canister. It comes with the vsv and all others. It's a complete assy. After so many years it's best to do it this way from all the dirt that gets trapped inside it not to mention saturation. Dealer only item.
No drivability issues except with the ecm seeing mil 'on' condition, it never goes into closed loop, and monitors will never 'set'. Your gas mileage will suffer.

Thanks for the info.