O2 sensor mystery
#1
10-26-2016, 12:37 PM
O2 sensor mystery
Is this supposed happen:
I was watching my O2 sensor readings on my UG. At start up they front ones read exactly the same. In less than 30 seconds the passenger one steadily drops to where it reads 0.000 and then creeps back up when i step on the gas. The two never read the same when driving. I am wondering if I have a wiring issue with the passenger one. I have replaced it 3 times with Bosch from Amazon. I think Amazon gets the dregs, I have returned them multiple times assuming it was bad. I know others have had bad ones as well.
Does the illuminati have any thoughts on the down and back up readings?
I was watching my O2 sensor readings on my UG. At start up they front ones read exactly the same. In less than 30 seconds the passenger one steadily drops to where it reads 0.000 and then creeps back up when i step on the gas. The two never read the same when driving. I am wondering if I have a wiring issue with the passenger one. I have replaced it 3 times with Bosch from Amazon. I think Amazon gets the dregs, I have returned them multiple times assuming it was bad. I know others have had bad ones as well.
Does the illuminati have any thoughts on the down and back up readings?
#2
10-26-2016, 03:21 PM
Have you tried swapping them side to side? O2 sensors can be finicky.
I assume you're seeing DTC codes (at least pending). If so, it would be helpful to post them.
As you allude, the wiring can also be a culprit, particularly the connector. Would be good to isolate a wiring issue vs sensor issue, particularly since you say you've replaced it 3 times with the same result. Also would not hurt to clean the connectors with contact cleaner when things are apart, paying particular attention to corrosion or oil saturation, which can cause shorting.
It sounds like something is going while the sensor is heating up, based on what you're observing. It's also possible that it's starved for atmospheric air, which travels down through the wires, believe it or not. Soldering connections, gunk/oil buildup, etc, can prevent air for traveling down the wires into the sensor.
Based on your observation of a change when you step on the gas, this seems like a likely scenario, since you're temporarily creating an artificially rich (low O2) exhaust stream, similar to what's going on while the car is warming up and being fed extra fuel.
Watching a video like this may be enlightening and give you some ideas of what may be going on. It relates O2 measurements to what's happening at the time.
I assume you're seeing DTC codes (at least pending). If so, it would be helpful to post them.
As you allude, the wiring can also be a culprit, particularly the connector. Would be good to isolate a wiring issue vs sensor issue, particularly since you say you've replaced it 3 times with the same result. Also would not hurt to clean the connectors with contact cleaner when things are apart, paying particular attention to corrosion or oil saturation, which can cause shorting.
It sounds like something is going while the sensor is heating up, based on what you're observing. It's also possible that it's starved for atmospheric air, which travels down through the wires, believe it or not. Soldering connections, gunk/oil buildup, etc, can prevent air for traveling down the wires into the sensor.
Based on your observation of a change when you step on the gas, this seems like a likely scenario, since you're temporarily creating an artificially rich (low O2) exhaust stream, similar to what's going on while the car is warming up and being fed extra fuel.
Watching a video like this may be enlightening and give you some ideas of what may be going on. It relates O2 measurements to what's happening at the time.
#3
10-26-2016, 06:27 PM
If it is only the passenger side, and its done the exact same thing for all three O2 sensors you have put in there, and you have no codes then the problem isn't the sensor.
If the information above is correct, I would inclined to say you have a small leak on the passenger bank somewhere.
but then again ..... (see signature)
If the information above is correct, I would inclined to say you have a small leak on the passenger bank somewhere.
but then again ..... (see signature)
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