EVAP system leak

I am not the person doing the work or the diagnostic. I have taken it to a mechanic because gas started coming out of my vapor canister. The mechanic replaced my vapor canister but two days later it started doing it again. I took it back now the mechanic is saying it the fuel tank vent valve needed to be replaced to stop the gas from getting from my gas tank into my vapor canister. I just want to make sure the mechanic is right because of his misdiagnosis in the first place. Now I have to replace the new vapor canister I just bought because liquid gas got back into it and now I have to replace the fuel tank vent valve. I just wan to make sure that he's right this time and I'm not going to have to take it back to the mechanic again. Just want to ask if these are the only two parts that can be the issue?

Ya, I'm getting the vapor canister replaced for free the only thing I'm being charged for this go around is the fuel tank vent valve and labor to replace it.

Hey, well got the vapor canister replaced and the fuel tank vapor vent valve replaced filled my car back up so far so good, no leaking liquid fuel. But I will give it a day or two just to make sure. Thanks for the help and advice.

Hey, well got the vapor canister replaced and the fuel tank vapor vent valve replaced filled my car back up so far so good no leaking liquid fuel, but I will give it a day or two just to make sure. Thanks for the help and advice. Well sure enough after that I smelled gas again. Took it back and he said to bring it back and he'll look at it again. I told him if he would have done it right the first time I wouldn't have to bring it back again. He got mad at me so I took my car home lowered the exhaust and the tank found out that a hose clamp that went on the fuel line that connected the vape canister to the fuel tank vent valve was worn out. So we changed it I don't smell gas anymore. I'm waiting until Monday to find out for sure me and my roomy fixed it. I'm going to give that moron a piece of my mind a certified mechanic that says he's been doing this for x amount of years should know that a fuel line with a clamp should just slide right back on. I'm turning them in to consumer services because he should have caught that.

Well, now I go out to my car today and my check engine light is on throwing a p0411 code that says evap emission system incorrect purge flow and I have no Idea what that could be. I've had people tell me it can be as simple as a vacuum leak or purge valve or purge valve solenoid or wiring issue or it can be the computer sending the wrong information to one of the parts.

P0441