That smart ass answer wasn't nice of you.
sjs from Fiji,
To answer your question, the % codes and duty can be read a couple of ways. Supposedly you can use a dwell meter, but I've never tried it. You can use a digital volt meter. If you can find an analog meter with an impedence of 10 meg or more, that would be excellent. You need extremely high o\impedence test equipment here for two reasons. The voltage signal is so low from the sensor that you can load it down and get incorrect readings. If you use a low impedence meter in closed loop, you can load and damage the computer. There are also special pieces of test equipment designed for o2 sensor circuit testing. that is what I use. Maybe others on this thread can let us know what they use.