Oxygen Sensor Voltage Question

[ctaylor738]

I recently bought a 1984 280SL road warrior - 181K, sitting for a while due to clutch problems. Plan A was to use the drive train in my 280C. But I have fixed the clutch, and found that this is actually a nice car. Plan B is to make it my driver, so I need to take it in for a smog test next week.

Since this is a euro car, a converter, O2 sensor, computer, and frequency valve have been added. All after market. The sensor was unhooked when I got the car - looked like a rodent chewed through the wire. I tested the voltage, and got a nice fluctuating current around .098v. So I connected the wire and found that the idle smoothed out a bit, but it was pretty good to begin with. The frequency valve also started buzzing.

The sensor is a three-wire model with only the sensor lead connected.

The engine starts instantly, warms up well, goes great, and idles smoothly. If anything, it smells a bit rich when it's hot.

Everything I have read about O2 sensors is that they operate in the .15 - .85 volt range. Is this always true? Or do they come in different voltages and calibrated to the computer/valve? I have had opposing answers from two experienced techs. I am obviously trying to figure out if I have a bad sensor or the engine is running very lean, or if the system is just calibrated differerently and everything is OK.

TIA for any information.