Resealed the Charcoal Canister...P0446 Engine Light Code..What I did

So I got the P0446 code after replacing my muffler. My old muffler had a hole in it so I finally replaced it. Although where I'm from it doesnt matter so much since we dont do emissions.
Anyway, so I decided to reseal the charcoal box since thats what google said to do if that happens. But what is resealing doesn't work? What if the code comes back? Should I replace the whole canister? And I did pay a mechanic 50 bucks to check out my whole truck before all this and I called him on the phone and asked how much he was selling charcoal canisters...He said 900 bucks...but on ebay its only like 50 bucks. So any guesses why these are so expensive new?
But it isn't a necessity since again i dont do emissions to register my truck. And yes I did all the work myself. I am no mechanic but I know how to follow youtube tutorials.