What is the proper voltage for an O2 Sensor?
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Joined: Nov 2018
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From: Atlanta, GA
2001 S500 (W220) / 2007 GL450 (X164)
What is the proper voltage for an O2 Sensor?
I have a Scanner that can read live data. I am getting a P0432 error and I was told to check the O2 sensors first. Is there a way to read what they should be without just changing them in hopes that it fixes the issue?
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From: CA
11 ML550, 95 Supra TT, 14 Audi S4
The voltage from a properly functioning O2 sensor will swing back and forth very quickly in a range of roughly .3-.7V or so. You probably won't be able to tell if it is good or not by looking at the voltage on the scanner. https://www.aa1car.com/library/o2sensor.htm has a good summary of how they work and what they do. The O2 sensor after the cat is what the OBDII system uses to tell if the cat is functioning properly and if the sensor isn't reacting properly, it may flag it as a cat problem.
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Joined: Jun 2010
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From: Emmett, ID, USA
2007 GL450
The voltage from a properly functioning O2 sensor will swing back and forth very quickly in a range of roughly .3-.7V or so. You probably won't be able to tell if it is good or not by looking at the voltage on the scanner.https://www.aa1car.com/library/o2sensor.htm has a good summary of how they work and what they do. The O2 sensor after the cat is what the OBDII system uses to tell if the cat is functioning properly and if the sensor isn't reacting properly, it may flag it as a cat problem.
The downstream sensors are downstream from a lot of stuff: the cat, the upstream sensor, the exhaust valve, the combustion chamber, the spark plug, the intake valve, the fuel injector, the throttle body, and the MAF sensor. So what people usually should do, in the absence of other likely culprits, is fix things in the order of cost. Change the oxy sensors if they have 100k+ mi, clean the MAF sensor first. Plugs if > 100k mi. Upstream sensors if you can figure out how to get to them. Then maybe the cats.
Cats earlier if you aren't in Commiefornia or are willing to take a chance that the smog dude won't actually look under the car.
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From: Emmett, ID, USA
2007 GL450
