Question about 2000 Nissan Maxima

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Do you know what a H02S12 means cause I have 2 codes coming up with service engine light ?

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It means Heater Circuit for oxygen sensor bank 1 sensor 2. Basically the heater circuit on an oxygen sensor gets the vehicle into closed loop faster, compared to OBD I (on-board diagnostics 1) years earlier. Ultimately it helps in emmisions and fuel economy. Typically unless you have a bad connection in this particular O2 sensor, then you are going to find you must replace that particular O2 sensor.

Posted on Jul 17, 2009

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Heated oxygen sensor bank 1 sensor 2, what was the code numbers that came up?

Posted on Jul 17, 2009

  • carl Jul 17, 2009

    Slomad you are not correct, It depends on the diagnostic code of the o2 sensor malfunction the o2 sensor can be miss diagnosed with that theory, considering its function is to measure the oxygen level in the exhaust there are many factors to cause a false positive with a o2 sensor, like a bad catalytic converter, for instance especially if the code was o2 sensor slow switching e.t.c if the cat was bad it would provide less oxygen content. There are many other factors, you should study the lambada and what it means. I would also like to facillitate an exhaust leak could cause a false positive on a malfuntioning o2 sensor. That is what diagnostic is for. You mention a bad connection but what about a bad pcm or faulty wiring. Hope this info helps instead of just throwing parts at a car money is hard to come by with this economy.

  • slomad1956 Oct 22, 2013

    I said "typically" I didn't say always. And if the catalytic converter was bad he would have other codes in addition, not a O2 sensor heater circuit code only. If he had cracked manifolds he'd throw a code, but not for the heater circuit. Sure a bad PCM/ECM could be the problem, but without a scan tool or more information you couldn't say. And nobody said anything about throwing parts at it. A bad connection is a cheap fix, and replacement O2 sensor can be a cheap fix depending on the se?or or car line, but replacing PCM's, catalytic converters and the such is going to cost way more in terms of throwing money and parts at a car.



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I think the problem is from the Emission System, something must have gone worng with it. and sometimes it is necessary to check the O2 Sensor as well. But it will be better you scan your car with the computer and so as to know where the problem comes from, so the error code from the scanning will now indicate the repair to be done on your car. Kindly take your car to an Auto Service Center to retrieve the error codes and then ask then to repair it for you or you forward the error codes to us so as to know the best repair to be done on the car. Thanks

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