PeteGT2857

Would I really need an Ocillator to check my Snesing part of my Rear Heated Oxygen Sensor? couldn't I just use a voltage meter? It's a pretty simple sensor. and I doubt it works off of frequencies than voltages. What doy ou think?

pete

Daniel B. Martin

The sensing element of an Oxygen Sensor cannot be tested with an ordinary meter, but it may be tested with a special-purpose tester or an automotive oscilloscope.

The signal from a healthy sensor varies from a low threshold (around 0.2 volts) to a high threshold (around 0.8 volts), and it sweeps back and forth between those extremes about 10 times per second. If a scope trace shows the Oxygen Sensor signal failing to reach either extreme, or oscillating between them at a frequency slower than 10 cycles per second, that is evidence of a "tired" sensor. If your voltmeter is one of the fancy models (Fluke 87, etc.) you may be able to use it in lieu of a scope to make this evaluation.