What is an oxygen sensor in a car? What does it do?

My Service Engine Soon light came on? I had the dealer run a diagnosis and he said it was a bad Oxygen Sensor? What is it? And what does it do? PLEASE HELP?!?

8 Answers

  • Anonymous
    1 decade ago
    Best Answer

    It does what it sounds like it does, it measure the oxygen content of the exhaust gassses. and by doing this it can determine the Lambda/AFR that the engine is comsumming. Giving this info back to the ECU which can then adjust Fuel accordingly.

  • 1 decade ago

    before I replace it I would disconnect the positive battery cable for 1-2 minutes then connect it again. this might clear the trouble code on the cars computer. if you do this and the check engine light stays on then i would replace the sensor. I have done this and 4 out of five times the light goes off (lucky perhaps). if you have to replace the sensor it is generally in the exhaust manifold, some newer cars have up to 5 or six O2 sensors in the exhaust system. What they do is tell the engine when it is burning rich or lean. With it not functioning right your gas mileage will be less

  • 1 decade ago

    the upstream oxygen sensors are for fuel control and the down stream sensors are catalyst monitors.the upstream O2 sensor tells the computer if the exaust gas is rich or lean and makes corrections by lengthening or shortening the fuel injector pulses from the computer.when an upstream O2 goes bad it will make your car run poorly and will effect gas mileage drastically.the downstream O2 sensors are monitoring the catalytic converter for deterioration.when a (cat) goes bad it no longer has the ability to hold oxygen,and emits raw fuel into the atmosphere, and turns on the check engine light.I am a master automotive technician and I do that kind of work everyday.

  • 1 decade ago

    An oxygen sensor/air fuel ratio sensor helps the car's computer determine the proper amount of fuel/air/spark (combustion) for optimal performance. If it goes bad the car will run at maximum mixture of air/fuel/spark which will reduce performance and can eventually over a long period of time damage your catalytic converter. Depending on the type of car it can be cheap or expensive, can have one or up to four sensors. If it is an old car and you don't plan on keeping it for several more years just continue to drive it that way if you don't have to pass an emissions test. If it is a newer car then you will need to fix it. You do need to determine if there is more than one on your car and make sure which one needs replaced. You also nee to make sure you have the proper sensor. There are several types and if you get the wrong one it can actually ruin your cars ecu/computer because of improper impedance/electrical output.

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  • 1 decade ago

    It measures the amount of carbon monoxide being put out your exhaust.It looks much like a spark plug and screws into your exhaust pipe usually somewhere just behind th engine.

  • 1 decade ago

    tells the injectors to rich (more fuel) or to lean(less fuel) the fuel to correct engine fuel air mixture

  • 1 decade ago

    Your Talking to much on the cell phone.and using to much oxygen inside your car.Thats way the little light came on.Becareful.

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