If ur BOV is mounted on the throttle body piping then it have no choice but let the air out, thats if the BOV is working. I had an immitation HKS BOV n it didnt work at all on both sides. So i ordered God Speed BOV and it release air like hell. My BOV is on the throttle body piping infront of the throttle body. Also make sure u hook up a vaccum hose to the other end of the BOV too.