It is inserted into the passenger side valve cover. It has a "thumb sized" rubber hose connected to it.
On the valve cover, with a large vacuum hose attached
You can find the PCV valve for your 1997 Mitsubishi Montero on top of the engine. The PCV valve will be in front of the air cleaner housing.
On the pump
Lincoln Navigators didn't come out until 1998...
It is just below the lower radiator hose.
If I'm not mistaken, it does not have a pcv valve, my 2000 doesn't have one on it...
If you don't have a shop manual, your nearest Lincoln or Ford parts department.
it's in the intake plenium, in the rear center. Its black plastic and has a hose attached to it that goes into the valve cover.
Each cylinder has its own. Remove the covers on the valve covers and you'll find them there.
Purchase a Purolator cabin filter as it comes with complete instructions. You may find your Lincoln does not even have a cabin filter.
On a ( 1998 ) Lincoln Navigator : firewall 4 - 8 3 - 7 2 - 6 1 - 5 front of vehicle
Someone with a service manual should chime in, it will be in there.