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"
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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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