The recommended way of doing it is NOT through the PCV Valve - and not through the throddle body. One of the vaccum hoses in your throddle body is the way to go. What you do is you have to find one that sucks in air. Spray the Seafoam into a cup and then use the vaccum hose to suck it in through there. If you pull out your pvc valve while your car is running it will cause your car to jerk and stall because of loss of pressure. Believe me - i've done it on accident.