Check on
Ebay L1H1 search for the L1H1 O2 sensor or
Oxygen Sensor Warehouse if you don't find that anyone has a good used one for you. Both places have the new ones for ~$180.
As for the matching Harness.... there is a seven pin connector on the front end of 94+ Integras that resides just under the upper radiator support that works with the L1H1. It's the connector to the left of the number 14, it's part of the "Cabin Harness"
If you don't have a junkyard near by that will let you cut up a wiring harness, I do have a spare connector (OEM cut from a VX harness with ~8" of wire on it) for the L1H1 that I can sell you.
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