I'm guessing that the O2 sesnor wire comes into the computer through the wire bundle in the passenger side kickpanel. Is this right? I'm trying not to drill a hole through the fire wall.

You shouldn't have to drill a hole. When I installed mine I just found a rubber grommet where other wires were and just slipped it through there. I didn't splice it until the wire was close to the 02.

I have read several posts where people have had problems with odd gauge behavior when they splice into the O2 wire close to the oxygen sensor. Autometer AFR gauges also mention in the instructions to tap into the harness close to the ecm, and not close to the O2.

On my 92, I just tapped into it near the ecm since it was easier to do anyway. I think it was a purple wire, but check a wiring diagram before doing anything.