I've been getting EVAP DTC P0440, 41 and 46 on my wife's 2000 Camry (4cyl, 2.2 L) over the past year and generally have been able to get rid of them by fumbling around with the charcoal canister and vacuum hoses and clearing the codes. Now I am getting the same codes accompanied by a high frequency tapping from the air inlet port on the charcoal canister once the car has been driven for about 15 min. You can hear the sound inside the car - it's a whirring sound and I traced it to the air inlet port with a stethoscope. I'm hesitant to replace the cansister because of cost and because I suspect the problem might be a VSV. Any ideas on troubleshooting this? Thanks.