O2 sensor reading .4 mv unplugged

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Jul 23, 2009 | 05:24 AM

pimpflea

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O2 sensor reading .4 mv unplugged

If I unplug the oxygen sensor wire, shouldn't the reading from the scanner be 0mv?

EDIT: sorry, .4 volts.

Last edited by pimpflea; Jul 23, 2009 at 05:50 AM.

Jul 23, 2009 | 08:31 AM

RBob

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From: Chasing Electrons

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Re: O2 sensor reading .4 mv unplugged

The .4 volts is correct. When the O2 sensor is unplugged, which is the same as a cold sensor, the O2 amplifier chip biases the output to 450 mV (or real close to that).

So seeing .4 volts with the O2 unplugged is normal.

RBob.

Jul 23, 2009 | 01:10 PM

camaro1185

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Re: O2 sensor reading .4 mv unplugged

Quote:

Originally Posted by pimpflea

If I unplug the oxygen sensor wire, shouldn't the reading from the scanner be 0mv?

EDIT: sorry, .4 volts.

Dont mean to hijack, but how do you scan the mv on your o2 sensor. Im running rich and would like to "scan" the voltage the way you did.

Jul 23, 2009 | 06:03 PM

pimpflea

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Car: 1990 IROC-Z Coupe

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Re: O2 sensor reading .4 mv unplugged

I am scanning it through the ALDL cable to my laptop (TunerPro RT).

Thanks for the reply, I wanted to make sure there wasn't a problem before connected the NBsim from my wideband.