if it`s the one by the rear of the engine  it should have a small green pcv 1 way valve on it  mine had broken at the valve,
look at the air filter box and check the thick air hose that goes towards the rear of the engine, and you can see where a pipe was meant to be connected on the top part  maybe sheared off but it connects from there to the pcv valve and to the part you are showing.
i repaired mine  but i have no idea what it does   nor did it make any difference to the running   on or off 
 
 
hope this helps