Not necessarily on the wiring harness. Check your drivers door sticker for the production date of your car. You might have one of the first 92'*. If so you may need 91 sensors.
If you know it'* an open/closed loop problem, the pcm may be the issue. I've seen a couple 92'* exhibit very odd problems that caused hair to be pulled out and as a final try the pcm was swapped, cured the issues.
Dan.. take a look in your HPT and see what temp we switch between open and closed loop. It can't be 20 seconds because it'* somewhere around 120 degrees. My car doesn't heat up quite that fast.
00 Regal GS: All kinds of cool stuff.