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Discussion Starter #1
Hi RR brothers!

I'm having a hard time with my 2006 RR HSE o2 sensors monitor.
Let me explain you the issue in details :

6 months ago I bought a code reader and decided to go through all errors codes.
After writing down on a piece of paper all P and U codes, I erased them (first mistake). :oops:

One of the codes was o2 sensor issue: Bank 2 Sensor 3. At that time, I did not replace the defective sensor. (second mistake).:oops:

Last week, I failed the smog test because of the o2 sensor monitors not being "ready". The smog technician advised me to drive the car for a few hundred miles and come back to test...after 800 miles, same issue! Monitors not ready.

At that point, I remembered the Bank 2 Sensor 3 code and decided to replace the o2 sensor. I went back to smog the car and : Same issue!8-0=8-0=
So, super angry at myself I went to a mechanic who "restarted" the computer and also told me to drive the car 50-60 miles and wait for a check engine light to pop.

But guess what?! 1200 miles later, still the exact same problem : o2 sensors not ready! 8-0=

I just don't want to bring it to a RR Dealer and pay $1,000 for a dumb monitor when the car is obviously clean and not polluting.

Any help would be appreciated! My registration has expired and I cannot get a sticker.

thank you guys.
 

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This'll sound strange, but try replacing the thermostat.

It may not be getting hot enough to heat up the cats and o2 sensors to be able to test itself.

(edit note) the temperature gauge will still be in the middle, it's an annoying thing to diagnose without replacing the thermostat.
 

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JACK'S GRANDAD
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Discussion Starter #6
This'll sound strange, but try replacing the thermostat.

It may not be getting hot enough to heat up the cats and o2 sensors to be able to test itself.

(edit note) the temperature gauge will still be in the middle, it's an annoying thing to diagnose without replacing the thermostat.
Thank you. It sounds weird indeed but it still makes sense.
Would a bad thermostat give me other signs or failure? like wrong engine temp reading or else?

I read somewhere that I could perform a "drive cycle" by following vague steps or going 55mph for 2 minutes, accelerating slow etc..
 

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JACK'S GRANDAD
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Plug into the OBD port with a half decent code reader, it will give the actual temperature the engine ecm is seeing from the sensors, without the buffered signal the gauge gets. And yes ANY OBDII compliant reader that has a live data function will work just fine

Martin
 

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This'll sound strange, but try replacing the thermostat.

It may not be getting hot enough to heat up the cats and o2 sensors to be able to test itself.

(edit note) the temperature gauge will still be in the middle, it's an annoying thing to diagnose without replacing the thermostat.
Thank you. It sounds weird indeed but it still makes sense.
Would a bad thermostat give me other signs or failure? like wrong engine temp reading or else?

I read somewhere that I could perform a "drive cycle" by following vague steps or going 55mph for 2 minutes, accelerating slow etc..
Unfortunately no, temperatures can be "normal", and the truck won't realize anythings acting up. It doesn't have a timer to realize that it's been on ongoing reset wait.

As leftlane said, try an OBD scanner with live data, if you don't have one, harbor freight makes an OK inexpensive option. I'll guess it'll say "Waiting for response" or something though.
 

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I'd just do a hard reset on everything then drive the car, you should be able to see if the readiness test completed with a diagnostic computer vs having to keep taking it to the inspection station. If there are no obvious problems I'm going to assume Cali has something similar to Ma. If you keep failing for emissions for no apparent reason or the thing isn't resetting there is a state facility the inspection shop can refer you to where they'll smog it etc to get you back on the road/ work around your issue. I go through this regularly with one of my other cars that's modified and on the fringe of legality.
 

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JACK'S GRANDAD
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Decent code reader will also have an I/M status, so you wont have to keep taking it somewhere.


Martin
 

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Bringing back an old thread - I have a very similar problem.

2006 Range Rover HSE, no check engine light. I replaced the battery about 8 months ago.

I/M Monitor on reader shows 1 O2 monitor not ready with 7 monitors ready. I have done all of the drive cycles listed in the Manual, to no avail. I have driven over 3,000 miles since this came up and my first trip to the SMOG station.

Unfortunately, my reader does not indicate which o2 sensor is potentially at fault - the live data shows all 02 sensors operating correctly. Also, the operating temperature is right around 200, which seems within the normal range.

Any idea on how to address this? I need to get my registration renewed sooner than later:)

Thanks in advance for any thoughts/assistance

Any
 

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First, it is likely that a defective thermostat will set codes, typically one for incorrect warmup. When you mention that ALL of the sensors show to be operating correctly, can you provide readings for them, and what the fuel trims look like? What is of importance to me here is the readings of the post cat readings. Do they follow the pre-cat readings? I doubt that this is a problem with engine temperature, as other codes would come up with the ones already mentioned. Let us know... Ray
 

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in PA your allowed to have one monitor not cleared
We clear codes and go for a drive cycle of 12 miles some hiway and local then check the monitors.
the vehicle is usually ready for the IM test
 

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I am curious is there was any resolution to your problem? I too have a 2006 HSE and the o2 sensor will not get ready. My reader indicates it is the downstream sensors on both banks. The live data for the downstream sensors seemed to indicate they were operating properly, showing a steady voltage up to about .9 under load; However, when throttle is released and car starts to coast the voltage drops to about .01. Additionally, the temperature behind the cat was about 20deg higher than in front. Despite reading what appeared to be the correct data I replaced the downstream o2 sensors as the cost wasn't unreasonable. This, not totally unsurprisingly, did not solve my issue. I put a few hundred miles on the vehicle and attempted to perform a typical drive cycle a few times. Still not ready. A few days ago I checked the static battery voltage and it read only 12.1v. The charging system is working correctly, so I swapped the battery for a known good one. I am not a mechanic, and consequently am not 100% confident in my understanding of the operation of this system. Would a battery at 12.1v be low enough to stop this monitor from getting ready without throwing a code? Is there a drive cycle specific to this vehicle? Should I change the upstream sensors as well?
 

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They might have other purposes but readiness codes prevent someone from resetting a code instead of fixing a problem and taking it in for smog. The codes has to clear and stay clear through a cold start and some distance of driving. If its "not ready", but you can't find a code, its probably an intermittent fault. The cat warm up process is likely to cause a problem like this, it did on my Audi. In that case it was vacuum leaks that took forever to find. But I have no experience with this on a Range Rover.
 

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Beat me to it. Why anyone lives there anymore is beyond me......rofl
Plenty of negatives for sure, I could move almost anywhere else and retire. But I love California. Kind of like driving a RR, hard to explain to those who don't :D
 

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Bringing back an old thread - I have a very similar problem.

2006 Range Rover HSE, no check engine light. I replaced the battery about 8 months ago.

I/M Monitor on reader shows 1 O2 monitor not ready with 7 monitors ready. I have done all of the drive cycles listed in the Manual, to no avail. I have driven over 3,000 miles since this came up and my first trip to the SMOG station.

Unfortunately, my reader does not indicate which o2 sensor is potentially at fault - the live data shows all 02 sensors operating correctly. Also, the operating temperature is right around 200, which seems within the normal range.

Any idea on how to address this? I need to get my registration renewed sooner than later:)

Thanks in advance for any thoughts/assistance

Any
 

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I have this same year 2006 Range Rover hse I have have a 02 sensor that won’t clear all others are green checked with no codes showing ever get to the bottom of your issue ? Please let me kno thank you
 

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Just an update on my situation... I have been to an independent RR specialist who has thoroughly diagnosed the vehicle as having no issues. Thousands of miles have been put on the vehicle and the monitor is still not ready. This is the first time he has seen this issue after 15 years working on these vehicles. As there are no codes and no diagnosable problems, the only response he could give me was the vehicle needs to be driven for it to clear the readiness monitor. Graciously, since he could not provide me with a satisfactory solution he did not attempt to charge me anything. The vehicle drives perfectly fine, has no codes and all other monitors clear within 30 miles of a reset (including the cat monitor, which takes data from the same sensors). I am stumped. If anyone with a similar problem had a more conclusive solution, please share.
 

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I have a 2006 HSE with just over 250K miles, and had the same issue, the O2 sensors would not set. Replaced them and drove and drove for months and they would not set. Tried lots of shops and smog places, they all said to just keep driving. Finally I found an Independent LR shop who said you need to clear the engine adaptions in order for them to set. He cleared the adaptions and within a mile from the shop, they set. Finally!! As he explained it, the adaptions slowly adjust the acceptable limit for various readings adjusting for expected wear on parts, once the old O2 sensors fell even outside that range, they just wouldn't set, but by replacing them with new ones and not resetting the adaptions, the new ones were outside the expected range in the other direction. Not sure about that, but it worked! The original shop that replaced the O2 sensors said they cleared the adaptions, but they use a more generic software tool, maybe it didn't work on a Land Rover.. or maybe they didn't want to admit they didn't know to reset it. At any rate, hopefully this helps someone else.
 
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