Toyota Repair: check engine light-2002 corolla


Question
QUESTION: I have a 2002 Toyota Corolla with 65,400 miles now.

In May check engine light went on. Friend turned off light that said emissions. Bought new gas cap at Auto Zone.
At 64,051 light back on-took to Toyota service. After two days they put in VSV valve $355.00. At 64,975 light back on they put on Toyota gas cap. They said if light goes on again they will have to drop gas tank with a big price.
Light on again at 65,400 miles.
I have heard a whistle or rumble when I remove the gas gap after
the light goes on. Any ideas ?  Bill

ANSWER: Hello, I need the specific code numbers from the computer please.

---------- FOLLOW-UP ----------

QUESTION: The code number at the first visit when they put in the vacuum valve at 64,051 miles was PO442.
 Thanks, Bill

Answer
The 442 code is a small leak in the evap control system, it can actually be found by doing a "smoke test" for a lot less than removing the fuel tank,it involves using a machine that pressurizes the system with a visible smoke, it may only need an evap charcoal canister which is common it could also be a leak at one of the hoses.