What does this connector attach to (1990 D21)?

[csem16]

Was reinstalling the heat shield on the exhaust manifold after changing the o2 sensor and had to unplug/remove a few things to get it in. I cannot for the life of me figure out where this connector goes.

It's bundled with the connector to the o2 sensor and both wires run into a plastic membrane in the wall of the engine compartment behind the driver's side headlight. It doesn't stretch any further than the distributor, compressor, exhaust manifold, but I cannot find any socket or connector. This is a 1990 D21, 4-cyl, KA24E.

Any suggestions would be much appreciated. Thanks.

[boriquaS13]

Oil pressure switch harness?