Hello and thank you for choosing just answer.
If the smoke is coming out of the collar that is a part of the filler neck then probably that's what's leaking and the filler neck needs to be replaced. They are very common to rust and leak. Replace the filler neck assembly which can be bought at any toyota dealership it will come with the line that goes to the canister. Make sure you secure all clamps and re-smoke to make sure that everything is sealed and re-run the monitor.
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OK you did not state that you replaced the fuel neck in your original question.
OK there are two hoses other than the big one that are on the filler neck, one goes directly to the fuel tank. and the other one that ends up going to the canister has a round object that it passes through first which is the fuel overfill check valve. Is the fuel overfill check valve is the source of the smoke when testing the evap?
Refer to this diagram and tell me which part is leaking the smoke if it's not what i'm talking about