Heated O2 Sensor

[mjdemaris]

Question: What should the ohms be on a good HO2S?
On my Suburban, I have 4.5, but on my 2000 Montana, 3.4L, I have 5.9.

Mike

[Tech II]

It might vary by different O2 sensors, but as long as you are getting a good reading I would think it's ok.......13 volts(car running) dived by 4.5 ohms equals 2.9 amps which is well below the 10 amp fuse.....

What problem are you having? Is there a code set?

[mjdemaris]

Code is P0137

[Tech II]

You do realize that this is a code for the O2 sensor, AFTER the cat, not BEFORE?

This code states the voltage is staying low......O2 sensors have two circuits, a heater circuit and a sensing circuit...measuring resistance has only to do with the heater circuit.....all the heater circuit does, is get the sensor to start operating sooner from a cold start......so resistance has nothing to do with this code....you either have a bad O2 sensor, or an opening in the harness to the sensing circuit of the sensor....