02 sensor / p0141

[srozing]

2003 Expedition Eddie Bauer / 5.4L

My CEL came on with a p0141 code - Sensor bank 1 sensor 2 problem. I picked up a new OEM sensor and put it in yesterday and it seemed like the problem was solved. Today, after say 7 or 8 drive cycles it came back on with the same code. What next?

I was watching the live data on the drive after it came on and it seems to be showing a normal voltage, mostly up around .7-.8v - my b2s2 sensor seem to be consistently maybe .05 or .1 lower. But maybe I'm barking up the wrong tree.

Any ideas?

 

[Fanatic1074]

2003 Expedition Eddie Bauer / 5.4L

My CEL came on with a p0141 code - Sensor bank 1 sensor 2 problem. I picked up a new OEM sensor and put it in yesterday and it seemed like the problem was solved. Today, after say 7 or 8 drive cycles it came back on with the same code. What next?

I was watching the live data on the drive after it came on and it seems to be showing a normal voltage, mostly up around .7-.8v - my b2s2 sensor seem to be consistently maybe .05 or .1 lower. But maybe I'm barking up the wrong tree.

Any ideas?

Sounds like u may have a plugged cat. Cats can cause issues with O2 sensor readings.

 

[srozing]

Hey thanks a lot for posting. I haven't suspected the cat, I have no problems at high RPMs and this thing only has 85000kms (~50k miles) on it. Engine otherwise runs totally smooth, I just don't like driving around with my CEL on. I'll take a look at this.

How do I go about testing power to the 02 sensor wires? Seems other people have suggested that as the next thing to check after having replaced the sensor itself. But if that was the case, wouldn't you expect the code to come back immediately (or maybe after a couple drive cycles)? The new sensor seemed to last a day or two and then it's coding again now.

 

[Fanatic1074]

Hey thanks a lot for posting. I haven't suspected the cat, I have no problems at high RPMs and this thing only has 85000kms (~50k miles) on it. Engine otherwise runs totally smooth, I just don't like driving around with my CEL on. I'll take a look at this.

How do I go about testing power to the 02 sensor wires? Seems other people have suggested that as the next thing to check after having replaced the sensor itself. But if that was the case, wouldn't you expect the code to come back immediately (or maybe after a couple drive cycles)? The new sensor seemed to last a day or two and then it's coding again now.

Yea with that low of milage cats are not likely but still possible. As far as testing the wires they only way you can really do that is by testing the resistance on the wires. I dont know what the resistance should be sorry, dealer may give you that info, if your luck. Most of the time they just say... Bring it in we will look at it... :-(.

As far as the codes coming back, The ECU will not throw a code right away. The code will stick in a pending status for a while until the ECU deems it a proper time to throw the code. Some codes can stay in pending for weeks depending on driving habbits and the frequency of the issue.