Okay everyone, I've changed my PCV valve. Since none of us ever seems to have done it, I took pics and notes for instructions. Here's the instructions. The Subaru part number is 11810AA000. I don't know how much it costs, sorry. Once you get the old one out, I'm sure it would be okay to just clean it.
- Purchase a 19mm crow's foot. $6.50 at a local wholesale tool store.
Hot tip #1 - A better tool can be made by heating up and bending the box end of a 19mm wrench to approximately 60° as shown:
- Remove the center cover on the intake manifold. It takes a 4mm allen wrench.
- Pull the hose off and remove the valve.
Hot tip #2 - You are actually unscrewing the valve upside down. Set your ratchet as if you were trying to tighten something.
Hot tip #3 - I was going to say "don't drop the crow's foot under the manifold, it's a bear to get it out". After dropping it three times, my new tip is "secure the crow's foot to the extension so you won't drop it". I used some electrical tape, since I'm out of duct tape.
- Clean the old one or install the new one. Once again, be careful not to drop it. I was able to start threading it by reaching in from the driver's side, towards the back of the engine, under the manifold. It was a tight fit, but easier than trying to start it from the top.
- I also pulled the hose out and cleaned it while I had everything apart. The hose was stiff enough that I was able to push it back on the valve by pushing on the other end of the hose, where it attaches to the splitter, which you can see in one of the photos.