O2 Heater Circuit
the O2 heater circuit is what makes 4wire Oxygen Sensors different from 1wire sensors. The heater circuit helps the sensor stay in its optimum temperature range so that it reads accurately.
Adapted from pgmfi.org wiki
the O2 heater circuit is what makes 4-wire Oxygen Sensors different from 1-wire sensors. The heater circuit helps the sensor stay in its optimum temperature range so that it reads accurately. See One Wire To4 Wire O2 Sensor for information on adding circuitry to an ECU to support the O2 Heater Circuit. See the Rom Maps for information on diabling the code 41 present when it is absent/malfunctioning.
Credits and source
Authors Anonymous PGMFI contributor
Source Adapted from O2 Heater Circuit on pgmfi.org wiki. Licensed under CC BY-NC-SA 1.0.