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Old 11-26-2016, 04:07 AM   #1
hondaeater69
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Default 02 sensor readout is in mA?

i'm going through a diag process on my front 02 sensor, and according to denso the sensor should fluctuate from .1 v to .9 many times after 3-4 minutes warm up. reading AF sensor cur on the AP, mine seems to stay -.1 to .1, but at the bottom of the ap readout it says mA, i'm guessing this means milliamps... is it reading in milliapms when all the specs are in volts? .1 mA is .0001v?
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Old 11-26-2016, 04:45 AM   #2
oaklandish_WRX
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It's O2 sensor voltage that is key, I always thought. FSM diagnostics, if memory serves, are the voltage waveform. Without knowing the resistance, it's hard to say what the current should be. the current might be the heating current if our sensors are the heated type... totally unrelated to your AFR.
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Old 11-26-2016, 05:10 AM   #3
hondaeater69
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the resistance at pins 1-2 at the 02 sensor is 3 ohms. the sensor is the heated type. my question is, can i test the functioning of the front 02 sensor by reading AF curr on the AP, or is the reading meaningless?
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Old 11-26-2016, 02:38 PM   #4
Airboy
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The rear O2 sensor bounces between 0.1 and 0.9V while for the front O2 sensor, the ECU reads the current and converts that to Lambda/AFR via a look-up table.
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Old 11-28-2016, 01:43 PM   #5
hondaeater69
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ah ok. yea i think i was looking at the spec sheets for 02 sensor, not AFR sensor . i did get a chance to look at another car's ap readout of af curr, and dam theirs is a lot faster than mine, and has more range. theirs was going into the 1mA at idle, where as mine never really moves above .2, and -.2.... even though my afr's are swinging all the way to 16:1, and 13:1.... his was staying solid at 14.7 but yet swinging the curr max min had a lot more range... weird.

maybe i'll pull the front sensor and put a torch on it.
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