For all its quirky faults, nothing about my DII has baffled me through the years more than O2 sensor failures and conundrums.

First, it seems to me that O2 sensors fail in the DII far more frequently than in other vehicles. Why is this the case?

Granted, my sample set is small, but I've never had one fail in any of the other cars in the family - an '05 CR-V, an '06 Accord and an '08 Lexus RX, all with ~120K on the clock.

In the 16 years and ~145,000 miles I've had my '99 DII I've bought and installed at least eight pre-cat O2 sensors. On top of that, some of the Bosch 15175 sensors have been bad out of the box. (I know we're all supposed to be using the Walker O2s now - I just don't find them locally and I'm not usually in a position to wait.)

But on a related note, when I looked online today at Amazon, I found several O2 options that are not Bosch or Walker. They start at $15.99 and five are under $30. The brands listed are Okay Motor, Scitoo and Kwiksen. Do any of you have experience with these brands of O2 sensors, in your Discovery or in any other vehicles?

 

My 2002 has original o2s with over 200k on them, still read fine truck runs great and has perfect 16-18mpg fuel economy.

Most cheap o2 sensors do not work, they either are incredibly out of tune, or are DOA.

 

I had some O2 sensor issues on my Kalahari when I first got it. I went ahead and replaced both the pre cat O2 sensors & they did the same thing (previous owner said he’d changed them out 5k earlier). I cleaned the connectors, and had the same results. Put the original O2 sensors back in as the new ones made no difference. Then I was up at my friends shop picking up some parts and I borrowed the T4 and reset the adaptive settings. It’s been nearly 3 years and 15k later and not a single O2, MAF fault since. I’ve always recommended doing that whenever you swap the MAF or O2 sensors.

 

Best, is it possible to clear the adaptive settings without Hawkeye/Testbook?

 

The Delphi software I have that SuperSport promoted here a few years ago has a provision to reset the adaptive settings but I couldn't get it to work over the weekend. Perhaps I'll try again next weekend, hopefully bringing more patience to the effort.

I'm still interested to hear from any others who have had actual experience with some of the lower priced O2s on Amazon that I noted earlier. Best, what brand O2s are in your DIIs?

p.s. I got a new Bosch 15175 today and bench tested it before I installed it in the truck. The bench test was positive, and the UltraGauge shows the voltage fluctuating as it should. All good. For now.

 

I run nothing but Bosch in my D2’s.