Toyota Repair: 4 Runner fuel codes, hydrocarbon emissions, emission control system

Question
I have a 2001 Toyota 4 Runner SR5. Recently my check engine light and my vsc lights came on. I went to Toyota and they said that the car had been fueled while running. That was possible so I thought it was fixed. A week later it came back on. I called them and they said they would have to put it back on the machine, and charge me again. I took it to another shop that only works on Toyota and Lexis cars with a great reputation. They said I was pulling several fuel codes. It says DTC P0441, P0446, or P0451 is output after DTC P0440 or DTC P0442 perform test for these before testing for DTC P0440 or DTC P0442. I don't have a clue. They said my canister was overfilled and needed to be replaced. We did that $513.00. Two weeks later it came back on. They said it could be the gas cap. We replaced it and now a week, later the lights are on again. The only thing I do know is since the lights came on, I often have a hard time starting it. It acts like it is not getting enough gas. This happens often but not every time. They said it is pulling several codes so it is hard to determine the exact cause. I can't keep replacing parts. Toyota also told me it was pulling several fuel codes. What can I do?

Answer
All of those codes are related to the emission control system, ie: the evap system which is designed to eliminate hydrocarbon emissions from getting into the atmosphere, all of those codes indicate that there is a large leak in the system, I admit that this system is kind of complicated and can be hard to diagnose, DTCs 440and 442 indicate a small leak but the 446 is a big leak, most of the time a gas cap that was not tight, there are ways to determine where the leak is by pressurizing the gas tank and running monitor tests on the evap system, it doesn't sound like the independent repair shop knows how to do this, even though there are many codes the exact cause can be determined it just takes time.
Don't replace any more parts!
Here is what I'd like for you to do:
Remove the negative battery terminal and wait 10 seconds and reconnect it.
Make sure the gas cap in clicked on tight.
Drive it like you do everyday and see how long it takes for the light to come back.
As soon as possible after the light comes back on have the codes read and let me know what they are.