Q: Evap canister replaced but VSC and check engine light are back on. There are no leaks.

My check engine light came on and I took it to Toyota for a diagnostic, was told it was my Evap canister. I bought a new one and had it replaced ( not at Toyota) drove it home, no problem. Drove it for about a week and everything was fine but one day the lights ( VSC check engine and the skidding car) came back on. Took it back to the mechanic that fixed it and he ran a bunch of tests on it and could not find a problem. He was able to get the light to go off on console and everything was fine. About another week later the lights came on again. I was thinking back to the times the lights came back on and I think it happened after I filled my gas tank. I never top it off, but could there be a connection between filling my gas tank and the VSC and check engine light coming back on? I would really appreciate your thoughts on this. I do not need to smog the car until August for registration.

My car has 96000 miles.
My car has an automatic transmission.