I need to get a new oxygen sensor and I am going to do it myself. I have the Service Manual CD and I printed out both instructions for replacing the oxygen sensor but they still do not give enough detail.
My question is:
Where the heck is it and how should I replace it? IE: Do I need to rip the carpeting out because I know it is in front of the passenger seat.
Well I just did mine on my 260e and the sensor itself is just before the catalytic converter on the exhaust pipe. The wires disappear up into the frame and I assume under the central console. Anyway, it came out easy enough. I bought a NTK sensor that just has butt connectors, so I had to cut the old wires and crimp them together underneath the car. What a job. Hope you have a lot of patience and experience. I think it would still be easier than trying to take the original plug out from inside the car. Plus it cost half as much as the full sensor + plug.
The O2 sensor connection is under the carpet of the passenger front, at the bottom of the transmission tunnel where it joins the floorboard. Lift out the carpet and you'll easily see it. If your going to use a replacement other than OEM, it is better to make the plug/connector "splice" reside inside the car.
1992 300TE 4Matic - Oxygen Sensor 
Linear Mode
