OK, here are the clues...:-\

 

1. 91 Legacy 5spd

2. EJ22 non turbo

3. located @ the front top center edge, below the alternator, in front of the " EJ22 " stamp on the block.

 

Have a guess yet???

Here are more clues...

 

4. It is approx 3" long cylinder mounted vertically.

5. It has an approx 20mm hex molded at the top for removal.

6. It is attatched w/a single conductor, w/a spade type connector @ the top.

7. It sometimes "burps" oil up through the center ( between the dialectric and conductor) and leaves your engine stinky when it warms-up.

 

Oil pressure sensor?

It is the electrical oil pressure sender.

On my car I've connected a T fitting to the port with the sender on one end and a copper tube on the other leading to a mechanical oil pressure gauge.

What is there to win???