Toyota Repair: Check engine light on, proper diagnosis, toyota service

Question
Hi Ted,
 First let me express my apprecitation for having someone who actually volunteers to give advise/info. The check engine light went on on my 2000 Solara, I took it to Toyota dealership and was supposed to run a computerized test for diagnosis, they tried to sell me one of the services many times and every time I get an attitude from them when I try to put it off for later. Anyway, to make the long story short, this time, after some time there the rep told me that it was the gas cap that was casuing the problem and that they reset the computer system to make the light go off, the diagnosis is SC code: 440, 441 and 446 and the charge description is 601 CPT which is only $45.00, not the 90 he mentioned in the begining for the computer check, I have an extended warranty and liked to have the problem fixed and I don't think resetting the computer did that and I heard from friends who had same problem and went to the same dealer for same service that they gave them the same diagnosis and the light came back on after a short while later. Could you please tell me if that is actually the right/proper diagnosis?

I appreciate your time and help.
Thanks
GG

Answer
Take it back to the dealer again and ask them to look up the Toyota service bulletin TSB EG013-03, there is a canister closed valve(CCV) that needs to be replaced, the bulletin explains the entire procedure. Replacing the gas cap is a nice try but not the problem.