OK, here is your answer from a guy that works on them everyday for a living....... I don't see many of those critters anymore due to the fact they are getting old and don't visit the dealers much anymore.
YES, it's in the back valve cover.
NO, you don't have to remove the plenum to get it out.
YES, it's kind of an SOB, but it can be done without a lot of cussing.
Here we go......
Take the 4 retaining screws for the air filter cover loose. You don't have to take the filter out nor do you have to take the hose off the throttle body. Just take the 4 screws loose so the lid is loose and will be able to flop around a bit.
Remove the engine side upper motor mount bolts from each upper mount. LOOSEN the other bots on each upper "dog bone mount", you don't have to take them out.
Get yourself a small "tie down" or "Ratchet strap". connect it from the engine mount located near the P/S pump to a sturdy location on the upper radiator core support. (You will be using the strap to pull the engine forward to give yourself some more room).
Block a wheel so that the vehicle can't roll when put into neutral. (Yes, it's a real PITA when you put i tin neutral and it goes rolling over your foot and running away). Put the vehicle in neutral and then pull the engine forward with the strap. You should be able to get a good few inches of space to help yourself.
From the under side of the plenum, there is a pipe that goes from the center to the rear. On the end of that pipe is a pre-formed rubber hose or elbow. The hose will start heading backward and then turn down very abruptly. On the down side end of that hose is the PCV. One half of the PCV is in the valve cover and the other half is stuck into the hose.
Remove the PCV, replace, and then let the engine flop back. Put the bolts back in the mounts BEFORE you put the car back in park. Tighten the mounts, put it in park, and re-attach the air filter cover.
Have fun