O2 sensor test method???

[Chalky]

Wondering if there is away to bench test on O2 sesnsor?? I found an 85.5/ 86 single wire sensor in the garage and want to see if it works?? Any suggestions???

[MikeFleming]

Careful application of a propane torch with a high-impedance, low-range DVM. With the DVM connected to the case (ground) and sensor wire (negative signal), heat the exhaust exposed shell to between 600 and 1200 F with the torch.

When the torch flame is removed from the shell, allowing atmospheric oxygen to reach the sensor element, voltage will go low (typically between 0.1 and 0.3 VDC). When the oxygen-free area of the torch flame is again covering the sensor element, all oxygen will be removed from the sensor and voltage will swing high (typically 0.6-0.9 VDC). The transition between low and high should be very fast, typically less than 0.5 seconds. Compare to new.

Note that propane torches will reach temps high enough to destroy a narrow band sensor so be careful when applying heat. Heat it slowly until there is a voltage and not much more.

Slow response is usually caused by silicon exposure, no response by metallic exposure (manganese, lead, zinc, etc.).