99 Camry 4 cyl code PO446

Scanner pulled code po446/evaporative emission control system vent control circut malfuntion.

i can clear the code but the check engine light will
pop back on in a day or two. The car starts/runs fine
whether light is on or off. The car has 105,000 miles

would appreciate any advice as to where to
start checking as far as repair.


thanx ted