hmm i dont know.

i remember when i first got the current subaru i have now, i went to scan an OBD code and got nothing from my scanner. i was like wtf how does that that happen. turns out i actually had two OBD2 plugs in my car. its not an issue anymore since i put in a different harness, but it sounds like you're dealing with a pretty big mess of a harness or whats left of it (just like i was).