2 Answers

PCV Valve locations:

1995-1998 3.0l - front valve cover

1996-1998 3.8l - rear valve cover

1999-2003 3.8l - front valve cover

INSTALL: Simply pull on the hose to release the valve from the valve cover - pull the valve out of the hose. Insert new valve and push back into valve cover.

NOTES:
The valve is in the end of 1/2" or so size hose inserted into a rubber grommet in the top of the valve cover

If the valve checkball rattles, it's working

Recommended replace interval - 40,000 miles

The 'other' large tube going into the opposite valve cover is a breather tube

it should be on the valve pan cover with a hose running to air filter duct or MAF(mass air flow) the PCV recycles the blowback exhaust back into the engine .
Answer

The PVC valve is on the rear valve cover closer to the driver side of the car. It's easier to see and get to if you pull off the air cleaner housing which is a hassle but once you get it out of the way, you can get to the PVC valve easier. The problem is getting enough leverage to pull it loose from the connector which has a rigid pipe leading to it. It's a snug fit and you have to be able to get a good grip to pull the old one out of the hose. It's fairly easy to pull it loose from the valve cover.

Wiki

It should be on the valve cover