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

Hi Ken, yes I need help how to change the filler neck.

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).

I have been getting EVAP codes P0441 and PO455. I put my smoke machine on and there was smoke coming out of the gas cap. I went to the local Toyota dealership and got an OEM gas cap for my car. That didn't solve the problem, smoke was coming out again. So I think it is the fuel neck gas filler hose. I been having a problem finding one for my car. I have a 2013 Toyota Corolla that was built in Mississippi. The VIN number is 5YFBUEEXDP197201. First of all do you think my diagnosis is correct and were can I find the part for my VIN number?

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.

I just went out and put brake cleaner on a microfiber towel and went around the the sealing surface with three applications of brake cleaner and did the smoke test. Smoke continue to come out, so that didn't solve the issue.

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.

I put plastic wrap over the gas cap with a rubber band securing it. Then I started my smoke machine. I took a video of what it did.

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.

No I can't see the under the smaller tube. I have ordered a new fuel neck from eBay that I will install.

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 got a new fuel filler neck from a auto salvage yard and installed it. That didn't solve my problem. I just got a new one and I tested it today and the video shows what I found. I contacted the first guy who I got the new one I installed and he said that it could be the charcoal canister was the cause. What do you think?

Here is what the guy said about the first fuel neck that I installed on my car:

The fuel neck was WELL inspected. I am 100% certain it is good. What’s causing your issue now is you fuel vapor canister. When they go bad, it creates a back pressure and pushes out the fuel neck. This is JR by the way. I worked at Al Hendrickson Toyota for 12 years so I saw this dozens of times. I’m certain of this and this also explains the code you got.

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.

He was right. I pulled the hose off the pipe leading to the gas cap and smoke cam

He was right. I pulled the hose from the canister off the pipe leading to the gas cap and smoke came out of the hose. I'm going to call Toyota and oder an OEM to see if that will fix my problem.

Please keep me updated.

First I replaced the fuel neck to the gas tank, then I replaced the charcoal canister 3 times, two brand new and the last one from a salvage yard and every time smoke came out of the gas cap. So nothing I tried fixed my problem. What could possibly be the problem?

Next, I would attack the area with soapy water in a spray bottle. You've already achieved the hard part. That's getting smoke to appear somewhere. Also, if there's a rubber hose as part of the filler pipe, use a hose pinch-off pliers to block the pipe.

I have been getting codes P0441 and P0445 that are permanent. The guy I bought the fuel neck from said that it was a charcoal canister issue. There is a hose that attached to one of the pipes on the fuel neck. I posted a video of smoke coming out of that hose above. I thought that meant that the canister was bad. I gave you more information. I can plug that hose and do a smoke test.

I don't have a better answer than what you got from JR. It sounds to me like the charcoal canister is blocking the free flow of vapors, then pressure is building up to the point it vents as intended or is forced out at a place that normally doesn't see very high pressure.

But I put on two new charcoal canisters and now a new one and they all didn't solve the problem. Buy you answer do you think it is upstream of the charcoal canister?

The only thing I have to go on is your observations and JR's recommendations. Try the soapy water and see what shows up.