The PCV,Positive Crankcase Ventilation Valve is to keep down crankcase pressure by way of venting the engine. Freon is the refrigerant that allows an air conditioner to cool properly. There is not any connection between the two.
Locating on a 1998 prizm - fine idea
The 1998 Chevrolet 2500 pickup truck has a Freon capacity of 5.5 pounds. You should never overfill the Freon in your cooling system.
r-134
44 oz or 3 freon cans
R134a
behind glovebox.
It is located just below the lower radiator hose.
unscrew it turn it to the left may need to use pliers if its on tight.
behind the flip out storage compartment by your left knee when behind the wheel
1-3-4-2
Buy a kit at Wal-Mart or auto parts comes with instructions
I would start with the spark plugs. If they've never been replaced, they're over due.