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Problems and Complications with O2 Sensors on 96 D1

5687 Views 36 Replies 14 Participants Last post by  Adam in NYC USA
Hello from Adam , owner of a 1996 D1 with 95k miles. :drive:

Since I purchased my Landi over the summer, I always had a minor annoyance. Every 100 miles, the Check Engine light would turn on. I got my hands on a OBD2 code reader, it gave me a P0130. Thats the o2 sensor on the drivers exhaust manifold. The O2 sensor was nearing its functional lifespan. With the onset of the late North American winter, the period of resetting the ECU are going from one a week to every other day.

I went to my Trusty auto shop. They go great work with my previous auto but I guess it is their first time with a LandRover. Asked for a price for a replacement o2 sensor. Their parts distributor was asking $290 for the o2 sensor and then $27 for the labor. They were cool. They said get the sensor and we will drop it in for you.

Today, I finally got a replacement O2 sensor (A LR replacement from for a great price ($105.00) and got it over to my trusted shop. At least it was trusted when I had a Mitsu Mirage. I ended up with a mechanic whose best description of electrical work is the Butcher Barber from Fleet Street. With a good working lift, I don't see why he had to butcher the sensor cables off the old sensors to remove the oxygen sensors.

He finally replaced the faulty oxygen sensor on the exhaust manifold, took out the downstream sensor for whatever reason is beyond me and put it back and now...........there are no oxygen sensor signal voltages going to the ECU. Put the OBD2 code reader on and read the stats and now the voltages coming out of all four o2 sensors are all 0.00. Now all I have to figure out is whether the butcher destroyed the harness that runs to the ECU (most probably he hit the ground return or dogged the harness to the ECU) or, worst case scenario of all, the ECU took a major hit in the A/D section. I don't look forward to getting a new ECU.

One thing I noticed when I had the Discovery off is that the code reader would continue to get information from the ECU. I didn't know that the ECU was on all the time.

When is this going to be fun?

Meanwhile, the engine is running thick and every 30 miles the MIL light lets me know all is not well.


Now what?

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1 - 17 of 37 Posts
No stupid questions just stupid answers....

scoobymick said:
I know this is probably a stupid question but I'm gonna ask it anyway!,can you see the connectors for the sensors,are they connected properly,or at all?!
HI again. :drive:

No, I reseated the harnesses going into the ECU. No effect to the ECU. The original problem was a old O2 sensor on the drivers exhaust manifold with the other o2 sensors working. Now, all the sensors are reading 0.00 by the ECU via the OBD2 codereader.

By the way, the action of the reseating also had the effect of resetting the ECU, so I now know it is not a software fault.

I am thinking,Either a damaged sensor harness or a damaged ECU. :dunno:

The Trusty auto shop is officially stumped. The "Butcher" states his cousin has a 95 D1 and he has "worked on it" but that is pre-OBD so not the same animal. The shop manager pulled all the stops with his computers and all he noticed was that the sensors are not being fed the proper voltage.

The shop was going to call a indie LR specialist today (Friday Feb 04) and asked me to call them back.

Sigh. :dunno: I have two more trump cards (two independent shops, one in LI and one in Mass) before I deal with my final result, the local LR dealer (Manhattan Ford).
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Carlos said:
A land rover is certainly a Very different vehicle than a Mistu. mirage.If you're doubtful about the knowledge of an independent shop in regards of Land rovers,DO NOT let them touch it.
Carlos, this is a trusted shop based by my prior expierence with them with other vehicles.

Your first sentence would make sense if they were working on a system on the D1 that was unique to the vehicle.

The emissions system is not unique. In North America, all cars except a minority of Extreme Low Emissions Vehicles (Honda, Toyota & Ford Hybrid) have to have computerised emissions monitoring and controls. The majority of them use oxygen sensors, ECUs and MassAirFlow sensors.

What is so special with the Discovery in regards to the emissions system. NOTHING. The engine down to the tranny are most the same for all SUV vehicles. Only when you get past the tranny does the design aspects change.

If I were to follow your argument, only LRs can travel on preapproved LR roads and parking spaces, hmm??

Carlos said:
Take it to the dealer, of course you will have to pay more, but will have a warranty, and it will cost you less on the long run than having different independent shops "figuring out" on your truck replacing unnecessary stuff.
Thank you Carlos but the repair does have a warranty but I would be a lot happier if everything was operating as spec.

If I had known that the 1996 D1 GEMS emission system were to be as fragile as an egg, I would not have taken it to my regular trusted shop.

Carlos, there are a lot of very good indie shops out there that do good work on Landies. The problem is finding them and getting untainted and truthful responses from satisfied customers. Both of the ones I know are more than 30 miles away. I know I have to leave the vehicle for overnight and take a commuter train back to the city. One is in Smithtown NY on Long Island and the other is in Springfield Mass.

Meanwhile, I am waiting on a shipment of a replacement ECU to see if that is the problem.
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Re: John C

John C said:
We just replaced the sensor on my partner's 98 D1, he had to go thru a few cycles before the new sensor was recognized by the ECU. Took about 10 mins to replace it and 4 or 5 cycles to get it working.
It's nice, but ALL the O2 sensors are working after the worn O2 sensor was replaced. Originally I had sensor readings before the worn sensor was swapped out.

The amazing thing about the D1 is that it is still drivable. It is in open loop mode and the Engine Light will only turn on when you raise the RPMs past 2500.

It is a testament of the engineers that they engineered that extra code in the ECU in case of sensor failure.

Meanwhile, the D1 is drinking slightly more gas and the accelearation is very strong.

Again, I am waiting for a ECU to swap to see if the original ECU was damaged.
re: o2 sensors

Unfortunately the trusted shop doesn't. They have Snap-On diagnostic computers good only for the Riceburners and the Motown stuff.
There is yet another good question.......

Jay B said:
Here's another "stupid" question: If they're not getting power, do you suppose he may have shorted something out and blown a fuse? I'm guessing this has already been checked, but you never know...
Something I learned and remembered from my days in electronics class in high school (1975-1979)comes to mind.

The very expensive electronic component, such as the $100.00 pass transistor, always protected the 59 cent fuse, by blowing up, when it should be the other way around.


Usually input circuits are protected from harmful voltages, and the ECU is even designed to know when the heater circuits are open or the input sensor lines are shorted.

I think the ECU made a very poor fuse.

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If Land Rover wants to help out its long term owners,

it should open the specifications of these propreitory tools or better yet offer consumer versions of these shop tools. LandRover is one of the few manufacturers of off-road vehicles where the majority of older vehicles are still on the road.

Whatever secrets that are in their older OBD2 has been out in the real world has no revelance in the 21th century. Many indie shops want to be able to fix whatever drives or is dragged into their shop. That is why there are new laws requiring automakers to open up their so-called trade secrets to the service industry.

A quick view on eBay shows many older LandRovers available for resale. If you want prospective future customers for your product line, make the proper tools available for your older automotive products. Once you got their product loyality, the happy consumer will come back to buy a newer model.

What is it with Land Rover with not giving a price break for product loyality anyway?
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LRWheelman said:
I don't think you will find Ford or GM giving a "price break" for customer loyality either.
I am guessing that you don't have newspapers in Missouri, although I had done an extended stint in San Antonio, TX. They had plenty of newspapers and cable tv there.

Most if not all automotive manufacturers have "customer loyality" pricebreaks. Jeep, in fact, is the only one I know that does not, but in its place, gives a $500 price break if you are in the military,law enforcement, fire, or EMS. Like that is a big help on a $36,000 Jeep. Lincoln, a luxury division of Ford (the new masters of Land Rover), usually does a model sale every January to move any sitting stock.

LRWheelman said:
And for so far as letting unskilled hands service my Rover, I would rather screw it up myself, @ least I will know what I did, so that I may repair it.
Well, the shop did not have "unskilled" hands, just "inexpierenced" hands. No reasonable dealership would let a rookie serviceperson on a service floor without a week of classroom work. The gentleman I was working with had considerable time in training and familiarity with several different makes and models. Unlike other shops, this one had considerable familiarity with other models foreign and domestic except in LandRover of course. Not that there are not any LandRovers in the borough of Queens.

I am not defending the service shop, however. The problem I am trying to fix is one that is rather exotic and not one prone to occur. Not that it would have helped. Within the time period of five minutes, they had all the recall memos from LandRover on their computer screen.

Then there is the matter of the age of the Land Rover (1996). If something was going to break, now would be a good time before hurricane season comes around. We are overdue in the Northeast.

LRWheelman said:
yada, yada, yada......Get a good, skilled Rover mechanic to fix it, maintain it well, and it should give you many years of good service. Thank You, LRW
In New York, as well as in the great state of Missouri, you will just have to "Show me".
However, is it great to armchair quarterback and have all the answers at your beckon call??
The Original Poster said:
Meanwhile, to all interested readers, the replacement ECU arrived today. Since the weather is very cold today, I will test the replacement tomorrow and report my findings.
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Update: Received Non functional ECU (Duh!)

Hi again from Adam in NYC.

Dropped in the "replacement" ECU for the 1996 D1. Car won't start. Put the old one back in. Vehicle starts. O2 sensor array still dead.

Oh well.

I am returning the replacement ECU back to the vendor. Now I am getting steamed. As soon as I am done packing it up, I am going to send out for a rebuilt guaranteed ECU and hope for the best.

More details as they arise.

Good luck to those with your minor problems.
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Manhattan Land Rover to Adam in NYC: Four O2 Sensors for $5000

Hello again from the Big Apple in NYC

I can say with total certainty that there is not a honest Land Rover dealership in New York City. I thought I could get a solution for my non-functional O2 sensors for my 96 D1.


Dropped off the 1996 D1 at the Manhattan Auto Group-Land Rover dealership on Thursday for the gas tank recall. According to LR, it should have taken about two hours. It took five days. They did not want to call me and got annoyed when I called them. The first day, they were annoyed and stated the gas tank alone took one day. Okay. Called me later and stated that the house of the mechanic had burned down and only he could work on the vehicle. Union rules. Call me on Monday.

Finally on Tuesday, they billed me for a new fuel pump for the new gas tank. $600.00. I asked them for an estimate for what was going on with the oxygen sensors. Sure.

They say that the oxygen sensors are ALL bad despite one was replaced and is shiny new on the exhaust manifold. They say the oxygen sensors were seized and unremovable and I needed new catalyst convertors. Funny, my Midas repair shop had no problem removing them. Hmm.

The estimate:$5000.00 for four o2 sensors and replacement cat(s). Hmmm.

No thanks.

For $600.00 they washed the exterior clean and brushed my alloy rims. Scratched the beluga black paint in three places and put a hole in the rear vinyl on the rear door. Also destroyed the bright alpaca floormat and left a nice oil mark on the leather drivers seat.


Somebody know a real Land Rover mechanic or should I go back to driving 50 or 100 miles for the real thing?

Adam in NYC
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On a good note,

The Land Rover is clean on the outside. :lol:
Its not the mechanical issue.....roverX

I live in a neighbrohood with no lifts and no repair shops, reasonable ones anyway. Born in a family whose had a uncle as a fleet mechanic, I grew up in a taxi fleet garage.

I liked Ford. My uncle worked on Chevys and adored GM. Dad had a Dodge. It made for interesting discussions.

in 1982, my Uncle Victor, the family mechanic, had a seizure and died under a taxicab in a street hovel he had set up as a ad-hoc garage. It did not help that he did not want to take his seizure medications nor that he used gas in a wood stove he used for working out in the cold. Had a seizure and died in a fire.

Learned quite a few lessions that day. Made me go to the Air Force and I learned not to cut corners whenever operating any equipment.

I became an Emergency Medical Technican for it anyway.

roverX, not everyone is blessed with wide-open spaces and a good safe place to do the work that has to be done. I am a urban cliff-dweller and I streetpark my Rover. Some of my firends still can't believe that.

Rescued plenty of street mechanics who were doing street repairs and had the toy jack give out on them. Some get lucky and just end up with bruised or broken ribs. Some others lose a finger, some lose more.

Got the blocks in the back and a nice collection of hydraulic jacks in the back. Most wonder why I got a garage in the back of the D1.

When something happens, most of my friends know I make one prepared Boy Scout.

Anyway, roverX, I need a mechanic with a Testbook. When all the o2 sensors were working and you change one and they all stop, you have a problem.

I have a problem here, Houston.
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John C, Clear your mailbox so I can send you some mail

On the road again, final post on this matter.....

Hi from Adam in NYC

Just finished with the Discovery. I went to Scott Dalton and he did his magic, after two weeks in the shop. The oxygen sensors (three had to go) and the wire got fried going to the ECU. The truck had ten years on it and a lot had to be fixed.

Shocks, springs, shock towers, oxygen sensors, and a new exhaust system had to be replaced.

Afterwards, the truck went to Robert Moses for a test drive(a piece of long beach like in California dropped in the south shore of Long Island).

It is a resurrection. It is not even the same truck that I dropped off.

Wow. Time to drive for the next 10 years and see what the future holds.

Adam in NYC
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pavel said:
Adam, don't dispair man - you'll get through this! As RoverX says, its better to do as much of your Disco work as you can YOURSELF.
I can't do it if I don't have a garage to work on it. I live on Manhattan Island and I also live in front of a police precinct. The police don't approve of street repairs and I don't like having an audience when I am doing my work.

pavel said:
Now what about your LR? Did the technician disconnect the battery before disconnecting the oxygen sensors? Do you have the correct sensors? Did the technician tamper with all 4 sensors? If none of your sensors are registering, did the technician leave some other wiring disconnected? I find it difficult to understand how the ECU got damaged. What about going over all the connections again...

Re: gas tank replacement on recall: I warned the local LR Dealer service dept. that if the fuel pump packed up within 30 days of tank replacement, they would be responsible. The job took 4 hours and there has been no problem after 3 months.
I had originally taken the D1 to a local shop just to replace one oxygen sensor. The knucklehead tech there said "oh, my brother has one too" and that should have been my first red flag. The second red flag was the schmuck poking at the sensor wiring with a huge screwdriver. After changing one oxygen sensor, all of the oxygen sensors were not working and the engine was running open loop and throwing the check engine light every 30-100 miles.

I had the correct sensor. Nothing wrong with the ECU. I was fearing that the nut with screwdrive may have blown out the sensors andwiring by hitting them with some live curent. Anyway,Had to replace the other three oxygen sensors. The truck is at 120 000 miles and look at the price of gas. Better to change them now and not worry for another 60 to 120 000 miles.

Scott Dalton of Expedition Imports ( is a gem and a rare find. Took care of the D1 and only real problem was getting the ECU to cooperate and pass the state inspection. He had to run it for about 150 miles before the ECU relented.
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Some months later.......Dead O2 sensor problems figured out but not solved

Hello again and time to beat a dead horse with a stick.

A quick go-around: I was replacing an oxygen sensor at an non-LR repair shop and when it was replaced, all my oxygen sensors went dead. They are all new.

Between the time of the last posts and now (about mid-March 2006), I was able to get some second-hand ECUs for the D1, all from eBay and nowhere near one price of $2500. (Addeum: One outfit actually sent me a dead unit and then stated that I did not know what I was doing. Only after I wrote extensively with no replies, did I contact Paypal, who promptly returned the money after I forwarded them all the emails.)

When I swapped out the old ECU for the replacement, the D1 started without problems. Installed my ACTRON OBD2 codereader and the oxygen sensors were working. Had access to an Autologic reader and before the swap thought the computer thought the car was pre-1995 with no sensors. It hung on the cat convertor diagnostic.

After the swap, the Autologic reader saw the sensors and completed the cat convertor diagnostic. The car drove as if it lost several hundred pounds.Got to try one of the ECUs I bought and the car ran fine until I parked it some 9 miles away. Then I turned off the car and tried to restart it. The car Check Light would not turn on and the car would crank but not start. I Had to be rescued and then put the old ECU back in.

Looks like someone messing with the old ECU blew something inside of my old ECU. Now, I have two strategies to think about here:

I have three ECUs. One is damaged and not reading the oxygen sensors.

I also have another ECU from 1998 or 1999 which I have not had the time to try out.

I could spend some time trying to find which ECU would work. I could also just send out the old ECU and have it repaired.

Anyone else have had this expierence?

How do I reset the replacement ECU so I can keep it for my truck? It almost sounds like copy protection, except the truck is ten years old.

Nothing quite like having a 30 hour day either. I woke up early to get this resolved to then get stranded for three hours to then go do my night shift until 6 am then to go back home and recharge my old bones.

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Thanks for the Post!

pavel said:
Adam - have a look at this UK site:
They say they only need 2 days to repair your original ecu, but how long it would take for shipping is another question. They show Range Rover but do not list Discos. I have no experience whatsoever with these guys. All the best.
From the US, you would have to add a week each way. There are plenty of ECU repair guys out there in the United States (my locale) . Just Google them.

I have a local guy who can send it out as soon as I can one of the others to cooperate. I wish I had access to a Rovacomm rather than a Autologic.

I also have to figure it out to properly do a ECU swap without getting stranded.

I have two more ECUs (one Discovery 1, and 1 Range Rover).
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