While changing my 98 2.2's temp sensor, I managed to break a vacuum hose nipple off a part close by. It's a 1" x 2" box with 2 vac nipples and an electrical plug, mounted with one bolt. I showed it to the Subie parts guy on their computer (I had to find it for him) and he says it's "some type of solenoid." No idea what it does, but depending on the VIN it's $68 or $118!! I was able to patch the old one, but will look for a junker or two. Any hint what is is? Thanks:)

I think it is a purge control solenoid. The other one may have to do with the intake area possibly. Both of them are there for environmental reasons.

 

I learned about them by doing the same thing you did. You have to be so careful when working around those valves. I ended up buying a new one for around $113 dollars. That was a discounted price too. There are other solenoid valves like from Nisson that will work and are a lot less money for a new one. You just need to change the wire connector.