its located on the top cover.. if u still have the tmic on u cant really see it..
basically its a positive crankcase vent.. what it does is vent excess pressure back into the plenum.. not the best of things as if it gets cloged with oil it can cause ur car to smoke.. besides it gets shit into the plenum...
to find it look @ ur plenum, on the right next to the throttle body ull see a black pipe connected to the top cover, remove that pipe & on the top cover ull see the pcv valve
kon