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Forum namePerformance/Engine
Topic subjectO2 Sensor Testing
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=110784
110784, O2 Sensor Testing
Posted by punker462606, Dec-04-08 11:04 AM
Ok I have found the wiring diagram for the front O2 sensor:
White-Black=Signal
Black-Green=Signal Ground
Black-Red=Heater Power
Black=Heater Ground

My question is I have read that you leave the sensor unplugged when you test the voltage, that doesn't make sense cause it needs to be plugged in to get voltage from the harness so you can even test out the voltage. It could be unplugged if your testing resistance but it needs voltage flowing through the circuit to test the voltage of the sensor. Correct me if i'm wrong. I'm trying to test this out right now so if anyone can get back to me quickly that would be sweet. Thanks.
110785, RE: O2 Sensor Testing
Posted by SilvrEclips, Dec-04-08 11:25 AM
Your correct. Unplug the sensor to test resistence and leave it plugged in to test the voltage.
110786, RE: O2 Sensor Testing
Posted by punker462606, Dec-04-08 11:32 AM
Thanks that what I thought. I was reading that and it just didn't seem right. Thanks again.
110799, RE: O2 Sensor Testing
Posted by punker462606, Dec-04-08 10:34 PM
Ok I checked the O2 sensor today and I started the car and the voltage stayed at 0.24V constant even after it got to normal temp and then it only changed when I revved the car and it never went higher than 0.48V. Now I never revved past 3000rpms. Which leads me to believe that is one problem. My question is would the O2 sensor go bad without throwing a code?
110803, RE: O2 Sensor Testing
Posted by SilvrEclips, Dec-05-08 08:58 AM
The ECU should be throwing a code for that. Not really sure why its not. After warming up the O2 should be bouncing between .9v-.2v or so.
110804, RE: O2 Sensor Testing
Posted by punker462606, Dec-05-08 10:48 AM
Thats what I was wondering. It just stayed at 0.24V i'll test it again just incase before I replace it but yead I have no trouble codes at all and I have horrible low rpm hesistation. When I start from a stop it just boggs down badly and then it wakes up after 4000rpms. Yay, more testing, I just want this car working again.