You need to read O2's with an OBD2 scanner which has a live readout.

Look at
http://jeffreyfall.com/landrover

There is a section there on O2's.

 

Oh, I am. Thats how I've gotten so confused watching it dive to zero in the space of 30 seconds once I start it.

So 2nd one from Amazon has the same issue. Just to be scientific and to rule out some sort of massive vacuum leak that developed while changing the o2s out, I swapped the front o2s. Same readings, same plummeting to zero - this makes 3 bad o2s now. At least I know its not the wiring, connectors, or engine.

1st was generic one - makes both upstream sensors read a constant 0.00, probably a internal short. Sucks, but not unrealistic
2nd - new Bosch - starts off good, but once you start the car dives to zero within 20-30 seconds.
3rd - new-new Bosch - same thing.
4th will be a Bosch from a local parts house - only one I can get quickly. fingers crossed.

-rj

 

Dear lord. I am cursed.

Sensor 4, same as the others - quick run to 0.00. This last one is a little faster than the others - about 10 seconds.

Bosch number 5 arriving tomorrow. This is just beyond dumb.

-rj

 

How long are you running/driving your truck before giving up on each of the sensors? I've had cases in the past where, after having an O2 sensor fail, it took five or 10 miles of driving to get the computer to, I guess, reset the adaptive values with the new sensor, or something like that. While it's true I was watching fuel trims and not the voltages directly in some of those cases it may be worth a try to take the truck out for a drive and not just shut it down after idling a few minutes.

 

Dirtnap- Your experience is a duplicate of mine. Mine would be fine on start up, and dive to zero. I would watch this happen on the ultra gauge. As I said before, the one that AB sells are from a UK company called Walker. They are what folks in the UK install after the factory one go kaput.
Land Rover Oxygen Sensor Replacement (Same Fit As Part # 250-24496)
I'm not flogging AB, I just know that since installed these I have had no issues.

 

Bosch number 5 was the same. I ran that around for 30 minutes of horrible driving - no change. Guy at the store was nice enough to go against policy and let me exchange it for a Denso. ABSOLUTELY THE SAME!

I'm going nuts. I'm going to order a walker from Amazon, but is there anything else I am missing? I am watching the voltages on the ODB guage, and they all do the same thing. If I swap sides than the problem swaps sides, which seems to rule out any wiring or computer issues. It's absolutely crazy.

-rj

 

Dirtnap- It really sounds like you have a connectivity issue going on as well. I know this may seem dumb, but have you totally cleaned the connections? Since LR's are prone to leaking oil, it can get into those connectors. You need to really clean them before you install. Also, you need to make 100% sure the connections are totally locked together. Shove those biatches together real hard, hear them click, and tug to make sure.
As I said before, I installed Walker's which I purchased from AB. I really think that the quality of parts from AMZN is second rate. O2's are not the only parts issue I have have with AMZN.

 

It is finally over.

I was despairing that the Denso sensor was also broken, but I had not received the Walker one I had ordered. For the 3rd time I switched sides, just to check. Sure enough, Denso still dive bombed, weird ebay one worked fine.

If you recall, one of the ebay ones I got made both readings 0 - some sort of internal short or something. Before I started with the multimeter and tackling the wiring, I decided to unplug the 'good' ebay one. It was the only assumption I had not really challenged.

Sure enough, with the ebay one out of the loop, the denso one acted fine. ARGH! Once the walker got here, they both work fine. I guess the ebay one had some weird voodoo impedence capacitance mystery short (that was electrical gibberish) made the other side look bad.

Thanks to everybody for all for your help - hopefully this helps someone at some point. Now I just wonder how many perfectly fine bosch o2 sensors I returned....

-rj

 

I really doubt you returned good bosch ones. I spoke to Amazon after the last go around with bosch. Guy told me that they were going to pull them from site because the fail rate was stupid high. It really makes me wary of ordering parts from them.

 

I don't think the problems you're having with Bosch sensors being bad out of the box are the fault of Amazon. Amazon gets its Bosch sensors from Bosch. Wouldn't the high failure rate be a Bosch problem? I've had problems with Bosch sensors I bought locally being bad out of the box.