Bench Testing Oxygen Sensors

[@joeteejoetee]

GREAT Video. On my Lexus LS400 1st sensor, the 2 white wires (~8.3 Ohms cold) connect to the internal heater element, and the Black and Grey wires connect to the Zirconium sensor element. These 2 wires have zero conductivity, nor any voltage at room temperature. On the bench (with Indoor breathing air) the sensor output wires (Black&Grey) produce a voltage ONLY when heated by the 2 white wires. The sensor even produces an output voltage (in room air) with only 5 volts on the heater. Room air is around 21% Oxygen, and they are very sensitive. This is why you need a Propane flame to reduce the amount of oxygen content for the sensor to read lower. Great Video - Thanks!

[@bensiemers5094]

Thank you. I am glad you found it helpful :)

[@kennethodonnell2068]

Nice explanation. Simple and to the point. No frills. I have 4 original O2 sensors at 175k miles. Scanner says which side it's on but which of the two is bad. The code also says it could be an exhaust leak. This will help me narrow it down a lot! Thanks!

[@fireboy5043]

Great Vid Thanks 👍🏽

[@pigeonsil240sx]

hello does this same test apply to AF wideband type sensors? thank you.

[@bensiemers5094]

That is a very good question. No, this procedure would be for conventional O2 sensors. Your procedure for wideband is quite a bit different. Unfortunately, I do not have content on that test, but there are posted videos elsewhere to assist.

[@commieslayer8218]

Very good and expanded tips for other issues - thanks so much.

[@xaker69]

I cant understand, how removed from car O2 sensor can generate 0,1-1V ? Please explain me

[@bensiemers5094]

The oxygen sensor is actually a battery that must be heated to work. When the exhaust warms the sensor adequately (or the heating element internally does), if there is a difference in concentration of oxygen, between the inside and outside elements of the oxygen sensor (anode and cathode) it creates a small voltage that can be read by the ECM. It is very quick to respond to changes in Oxygen levels as a result. By heating the end on the bench with a torch, and bringing it closer and further, because the torch uses hydrocarbons, the distance of the torch from the O2 sensor will vary the Oxygen levels available at the O2 sensors end, and therefore creates a voltage variation that can be interpreted. It should rest between .1 and close to 1 volt when hot.

[@larryreno8293]

ZrO2… Chemistry! And heat

[@fredjones1238]

explained well thanks

[@SamMorrow-cw6wz]

Why are you trying to be European ? I’m sure your car has a speedometer measured in “ miles “

[@bensiemers5094]

Canadian

[@Zeberka767]

My oxygen sensor has 4 wires, 2 black, 1 white, and 1 blue. How do I determine which wire represents the terminal of HT, +B, OX, E1?

[@bensiemers5094]

It sounds like you are using symbols from a specific manufacturer's wiring diagram. Each manufacture uses different codes and without seeing the actual wiring diagram, I wouldn't able to comment on that, specifically. You can look up the wiring diagram though and look at how the wires trace to the actual sensor to determine what is the heater portion, vs the sensor signal and ground.

[@mcrowley8460]

1133

[@paulygood6665]

I have 604,000mi on 2004 2.3dohc Ranger

[@bensiemers5094]

Wow! Those 2.3 rangers are bullet proof engines. I had a 2007 with a 2.3 in it. Tough little engines.