Just had a question. I have a 92 Camaro rs 305 TBI. I notice this buzzing when I turn the car off (could be when its running too but not sure there). a buzzing sound. today just found where its coming from, the purge canister the sensor (or valve if that's what its called) at the top where the connector plugs into. I know pressure from the tank relieves into the canister and is absorbed and reused when you start the car. So I loosened the gas cap so the excessive pressure comes out, was done so I retightened it and walked away. and then as I started to walk away I heard the buzzing. so I went back loosened the gas cap and more pressure was relieved. I know I had the car running, it is warmer out today but it been going on even when it was cooler. I just wasn't sure if the buzzing was my car or something else, because I paid more attention when I was out and about. the valve that goes from the pressure line to the canister I had replaced before , never the canister. I know some people take them off. but is this excessive or something that happens more often than it more normal? thanks