I just bought the one on ebay from "GLOBAL-AUTOMOTIVE" titled "NEW NTK OEM OXYGEN SENSOR 5 WIRE 1992-2000 HONDA CIVIC". I just installed it on yesterday. When I got it I noticed the wires looked a little short and the "honda part# sticker" looked a little out of place. Sure enough the wires were way shorter than the ones on my stock sensor. I accidently pulled some of the wires out of the harness plug when I tried to plug it in. I ended up cutting the harness off of my old sensor and joing it with the new sensor to lengthen it. I got it all together and started my car to find that it worked just fine. I drove a few errands in town and then took off for the beach for a 125 mile test run. So far no problems and my car runs way smoother. I don't know what the whole sticker thing is about (instead of stamped or ingraved!?) but the sensor seems to work fine. $79+6 shipping isn't too bad...
Couldn't get the nut loose with an adjustable wrench and no way of getting box wrench on it without cutting the wires so I am going to have the mechanic swap it out. Shouldn't take him more than 10 minutes, right? It was $40 for an o2 sensor socket wrench. Mechanic should be able to do it for cheaper.
I soaked and resoaked the nut in PB Blaster (over night). No dice.