tofino

I've read many o2 threads on this site, and there is very little I can find on this specific situation. My 86 4x4 pickup 22re is throwing an o2 sensor code. The sensor toward the rear of the vehicle has its wire chopped off. But my problem is with the front sensor. The wiring from it disappears into the body roughly under the area of the driver's seat. I saw one post whose author said something about removing floor panels to find the connector, but he was super vague and gave no details. I pulled up the carpet in front of the driver's seat and I see nothing at all that looks promising.
So, where, exactly, is the connector for my o2 sensor and how do I get to it, and second, are the front and rear 02 sensors the same identical part, or are they different? Thanks.