Engin?
Trans?
4WD+1354 TCase or 2WD wOut TCase?
If V6~4.0L~SOHC Engin & 5r55e Trans,
PCVValve is at rear end of left ValveCover next to FireWall, 1/4Turn Insert\Removal.
Plastic tabs in ValveCover commonly break if PCVValve is not inserted\removed properly.
Cure is a new ValveCover; can try temporary HeatShrinkTubing around PCVValve to make it fit snug in broken hole.
PS: edit your signature with basic vehicle specs: Year+Model+Engin+Trans+TCase+Diffs+..
makes asking+answering questions easier+quicker.