DIY: Measuring air/fuel sensor resistance

[81corolla]

For what it is worth here is how to measure the resistance of the air/fuel sensor to see if it's good or not.

Here's my writeup on replacing the sensor.

http://www.clublexus.com/forums/rx-f...el-sensor.html

One can measure the resistance of the front sensor, Bank 2 Sensor 1 without taking it out as it's right there in the front of the engine compartment. The back sensor, Bank 1 Sensor 1 is more difficult, but could also be measured without taking it out of car.

Do this when the engine is cold. Unplug the sensor from its socket. There's a small wire-tie you can undo to create more slack in the sensor wire to move it around.