What would cause an O2 to read 438mv?
10-21-2005, 12:20 PM
#1
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What would cause an O2 to read 438mv? What would cause an O2 to read a constant 438mv?
This is on a '97 V6 (3.8). One O2 looks to be fine but the other is reading 438mv all the time.
Is there a lower limit the PCM can report?
Is this what happens with a short or something?
Some work was just done (manifolds were off and on again) and the O2 worked fine before that.
Thoughts?
Thanks,
Mark
This is on a '97 V6 (3.8). One O2 looks to be fine but the other is reading 438mv all the time.
Is there a lower limit the PCM can report?
Is this what happens with a short or something?
Some work was just done (manifolds were off and on again) and the O2 worked fine before that.
Thoughts?
Thanks,
Mark
10-21-2005, 07:08 PM
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I'd look for a wiring open circuit, connector off,
maybe burnt wires. Something about if that O2
circuit faults, it will be pulled to center, I can't
remember the specifics, and I don't know that
much about V6s anyway.
maybe burnt wires. Something about if that O2
circuit faults, it will be pulled to center, I can't
remember the specifics, and I don't know that
much about V6s anyway.
10-22-2005, 10:04 AM
#4
Originally Posted by Mark99Hawk
What would cause an O2 to read a constant 438mv?
This is on a '97 V6 (3.8). One O2 looks to be fine but the other is reading 438mv all the time.
Is there a lower limit the PCM can report?
Is this what happens with a short or something?
Some work was just done (manifolds were off and on again) and the O2 worked fine before that.
Thoughts?
Thanks,
Mark
This is on a '97 V6 (3.8). One O2 looks to be fine but the other is reading 438mv all the time.
Is there a lower limit the PCM can report?
Is this what happens with a short or something?
Some work was just done (manifolds were off and on again) and the O2 worked fine before that.
Thoughts?
Thanks,
Mark
Good luck, Ed
10-22-2005, 10:06 AM
#5
Originally Posted by Ed Wright
Don't run out and buy a sensor, until you do some testing. No matter if it is a 4, 6 or 8 cylinder, you will see 430 to 460 mvs on the scan tool if the sensor is not pluged in. That is the reference voltage riding on the signal line. An open circuit is the likely culprit. If the sensor is connected, unplug it and check voltage again. If you see no change, you have a wiring or connector problem.
Good luck, Ed
Good luck, Ed
Good tip Ed, thanks for posting....
Bill Wright
10-22-2005, 12:33 PM
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Originally Posted by Ed Wright
Don't run out and buy a sensor, until you do some testing. No matter if it is a 4, 6 or 8 cylinder, you will see 430 to 460 mvs on the scan tool if the sensor is not pluged in. That is the reference voltage riding on the signal line. An open circuit is the likely culprit. If the sensor is connected, unplug it and check voltage again. If you see no change, you have a wiring or connector problem.
Good luck, Ed
Good luck, Ed
Will check for a dead wire somewhere.
Mark