Hi All,

Working on chasing an upstream bank 1 oxygen sensor code on my son's '01 Disco 2 and could use some advice.

He gets a p0130 on the Ultraguage - but I plugged in the Nanocom and get a P0134. Weird eh?

The Nanocom says:
P0134 = Lambda Sensor Upstream
Catalyst Bank 1 drive cycel C
Occurred 1 times
Signal invalid
Fault is currently present

Is it weird that the Ultraguage and Nanocom get are getting different codes? P0130 vs P0134

Reading that bank 1 upstream sensor real time shows 0.00 with no change. All three other sensors read as expected with values that fluctuate.

We visually verified that the sensor is plugged into the vehicle harness, and wiggled wires around to see if there might have been a loose wire. No change in the real time readings.

Now it seems unlikely that the same sensor was dead both before and after swapping them out.

I'm going down the road of two bad sensors in a row (unlikely to me), a broken wire, a bent connector pin, a damaged/corroded connector pin.

We'll unplug the connector, verify pin condition and test the sensor operation with the oscilliscope next, if we don't get any other ideas.

Are there any other more accessible connectors that I can test for the O2 sensor signal to troubleshoot that segment of the system? Or test for continuity in the wire harness?

Thanks for any ideas.

Note: We found a few vacuum leaks this spring by smoke testing and replaced the brake booster vacuum line, and a few other small leaks - then afterward verified all vacuum leaks gone. We recently replaced the MAF. And we did head gaskets last winter. We don't have any intake or exhaust manifold leaks, or exhaust system leaks. We also fixed a gross vacuum leak by replacing the gasket on top of the fuel tank where the fuel pump goes.

 

swap sensors left to right and see what happens.

 

P0130 is pending
P0134 actual code - no signal

Swap sensors as Extinct recommended but don't be surprised to buy a new sensor. Without re-starting the forum discussion of what brand is best, I've had good luck with Bosch.

 

Thanks gents. We'll start with swapping sensors. And thanks for making sense of the differing codes!

 

Thanks again for the guidance. The new bank 1 upstream O2 sensor was dead.

To limp along, we put a used working sensor in that position and it is working as expected. We get appropriately fluctuating readings when we observe it real time on the nanocom.

Very disappointing to have a new product DOA like that. I will reach out to Atlantic British to see what they can do for us.

 

I don't know what brand you bought, but over the many years I have had at least two Bosch sensors be bad out of the box. Others here have have the same experience. That's why I now only buy locally.

Many here report better results with Walker sensors. I'll buy Walker if I ever need to replace one again. (Knock on wood ...)

 

We got whatever generic sensor Atlantic British has in their kit, no idea of brand.

The only thing I could locally today is a Bosch, so will try it.

Is there a good bench test to verify function before installing?

 

Yes. There are YouTube videos about how to bench test an O2 sensor.

You'll need a multimeter to read voltage, a torch to heat the sensor tip, and a way to hold the sensor securely while performing the test.

I had a small bench vise when I did this years ago, but I suppose a pair of Vise Grips could be used in a pinch.

And yes, they are Vise Grips, not vice grips. Vice grips, is a misspelling I see frequently. That would be something else entirely! I don't know just what.

 

Thank you. The multimeter and propane torch test was useful. We did in in the bench vice.

 

What did the test reveal? Good sensor or not so good sensor?