Smoke coming out of the gas cap?

Yep, I would double check to make sure the filler neck is not damaged up where the gas cap seals against the cap. If so you will need a new filler neck, I would check ebay I have had good luck with parts form there.

P0441 (incorrect purge flow)
P0455 (large EVAP leak

That would explain these codes as well. Clear the codes when the repair is completed, let me know if you need help changing the filler tube out. Ken

First, drive the car until the gas is on empty or follow this video on how to drain the gas out.

https://www.youtube.com/watch?v=Q5MH2gnyFH0

You will need to raise the car up watch this video to do it safely.

https://www.youtube.com/watch?v=xLFn_bMkZc0

Then remove the clamp at the bottom of the tank, remove the filler tube mounting clamps and then remove the filler tube to replace it with the new unit. If you have problem please upload an image or a short video in your response, so I can see what's going on. Check out the images (below).

If smoke from a smoke machine is coming out by the gas cap, it sounds like you're using the tool correctly, and you've identified the source of the leak. Remove the cap, then look at the sealing surface on the end of the filler tube. It is somewhat common for a crusty film to build up over time. Try a solvent like Brake Parts Cleaner or Carburetor Cleaner on a rag to remove that build-up, then run the smoke test again.

Can you see any residue on the sealing surface? If it is perfectly clean and smooth, that just leaves the gas cap.

Also look for a small vapor return hose attached an inch or two below the top of the filler tube. The hose is commonly held to the metal port with a simple hose clamp. If the clamp is rusted off or if the hose is dry-rotted, smoke can leak out there too. The escaping smoke might appear to be coming from under the gas cap.

Next, remove the gas cap, then cover the opening with plastic wrap and a rubber band, then do the smoke test again. If you still see smoke escaping, it has to be from something other than the cap. Use plastic that is used for food as it is very thin and easy to form a good seal. Smoke machines only develop around 2 psi of pressure, so it doesn't take much to contain it. Let me know what you find.

From what I can tell, it looks like the leak is down lower and the smoke is just rising to where it can disperse. It looks like there's no smoke right under the plastic wrap. Are you able to see the filler tube from underneath? Look for that smaller tube and hose I mentioned.

Can you see from under the vehicle if there's smoke down lower? It's also possible to have a cracked / loose / rusted part on top of the gas tank, but by now I suspect you would have noticed gas seeping onto the ground when you filled it. Replacing the filler tube appears to be easier than on a lot of other models. We'll wait to hear from you. Please keep us updated on your progress.

I can't argue with what you were told. The question I DO have is we were always told smoke machines only develop up to 2 psi to avoid creating temporary false results. Can you find the charcoal canister and remove the vapor hose? That should make the smoke come out only there.

Please keep me updated.