The VSC Off light comes on by default with the check engine light. The B2799 means that an unregistered key was used. I would not worry to much about it unless it keeps coming back. Is the p0446 the code that is coming back this time? Auto Zone does free code reads so you do not have to pay the dealer again. The most common problem is the hose that goes to the CCV on the side of the air cleaner housing gets knock off when people change the air filter. Check the hose it is about 3/8 in diameter. The other issue is the VSV on the canister. Given the age it is not likely the canister. Someone does not know how to diagnose or they are too lazy to spend the time to do it right. Let me know about the hose and if you can get the code number again to confirm.
Let me know how it goes.
There are about three different codes that will fit the descriptions that they gave you. Did they give you any specific code numbers such as P0441 or P0446? The most common problem on the Highlander for these codes is a close canister valve which is mounted to the top/back side of the air cleaner box. If someone just replaced the air cleaner recently they probably popped the 3/8 inch rubber hose off of the bottom of this valve. Open the hood and check to see if this is the case. Let me know if you have the exact code numbers that they gave you or if this hose has popped off as I described.
Sorry to repeat myself about the hose on the canister I have three of these particular questions going and forgot that I all ready told you about that hose at the air cleaner box. Do you have the code numbers that are reset system this time?
No problem, this code will also set one up close canister valve or CCV as it is known by which is mounted to the side of your inbox sticks open. There have been a lot of problems with this valve on the air cleaner. You can remove the valve and vacuum test it and apply 12 V and ground to the solenoid to make sure that it is not leaking. Let me know what you find this valve.