I’d just leave well alone. Lots of us have that code to no ill effect  Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
My preferred specialist: www.glenrands.co.uk
--------------------------------------------------

DrRob, the fault code relates to one temp sensor in the N.S. manifold. Depending on how this sensor fails? Im guessing from one end of the temperature scale to the other? Some clearly don't give problems "like yours" whereas mine when it failed, it made the exhaust stink, due to overfueling the car! This filled the DPF with unburnt fuel and gave me no end of DPF regeneration issues!

I had mine replaced recently at Rovertune at minimal cost as part of a wider list of jobs being carried out. They replace a lot apparently on a regular basis so have the experience and tools to do it  Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
My preferred specialist: www.glenrands.co.uk
--------------------------------------------------

First its a thanks to everyone's contribution on this topic and I am pleased that I found it. I've had mine RR for three years without the dreaded message but it appeared a few weeks ago. What was pleasing in a way is that I'm not the only one and that members have the knowledge and are prepared to enlighten others! During my first service at an Ind. garage. I had a EGR sensor fitted - Dec 2017. The following year the service was done but they reported the P040D-00 error code and two sensors were fitted as they didn't get a regeneration after they fitted the first to the EGR. I looked back at their invoices to see these comments this week and the 10 hrs plus sensor costs. In fairness I was told "we have NOT done this before" and I didn't get a quote from them either. What may be of interest to everyone was that they removed the nearside front wheel arch cover and removed fuel filter and other bits (I'm no engineer) to do it. Just wondered if that seemed to be helpful to anyone?
Needless to say I decided to do what servicing I could do myself after the help gained from the forum membership. This way ensuring jobs were done and the right items such as oil etc were used. I have a good local garage for anything basic underneath!
I will watch out for the "FULL" message again but realise now that my driving style now retired, country lanes here and lock down don't help. Also to drive it as it is meant to be!
So thanks to all
Dave

Dave, many thanks. Like you, retired, not many long runs. Wow 10hrs, my Indy charges £50 per Plus how to decide which sensor to fit. More thinking to be done. 2013 SDV8 4.4 SE Luxor.
1960 Series 2 88 inch diesel.
1955 Series 1 86 inch petrol.

Like many others I have had this fault code showing for years.
I bought the replacement sensor 5 years ago but was strongly advised by the indi I was using at the time to leave well alone unless it really started causing any problems.

He explained carefully what work was involved , then told me the last one that they did cracked the manifold as they struggled to remove the old one.
I passed all the info onto Greg when he started this thread and decided to leave mine whilst the car was running well.

The new sensor is still in the box ,just in case
Mike. G reg 2.5VM Vogue Portofino red 1991- 1999
V reg 2.5td P38 Rioja red 1999- 2006
53 reg td6 Vogue Oslo blue 2006- 2015
11 reg 4.4 TdV8 Vogue SE. Baltic blue 2015- date.
https://www.fullfatrr.com/forum/topic56162...tty+affair

So can anyone put an estimate for a garage to fit one. Nylands said 10 hours plus. That’s prohibitive. Can I do it myself .? 2013 SDV8 4.4 SE Luxor.
1960 Series 2 88 inch diesel.
1955 Series 1 86 inch petrol.

I’ve just been down this route… there is a wiki section on replacing it.. it’s a rotten job, and mine broke off. So no chance of actually replacing it, without removing the actual manifold. I have a new sensor, and when plugged in, and left dangling by the manifold, it obviously clears the code alarm… however it doesn’t get hot there, and doesn’t do it’s job. So I decided to experiment, and heat up the sensor, and measure the resistance at hot temps. Took it all the way to red hot, and got a max resistance of 650 ohms. So I ordered a 650ohm resister, which I plan to fit on the wires that feed the knackered sensor. Ie cut the wires off, fit a resistor, and drive it. That sensor will then reads hot exhaust, and should allow a regeneration, when other factors allow.. ie other sensors, speed etc. when I get the thing fitted I will report back. For what it’s worth, I’m not planning on removing the manifold as it looks a hell of a bad job, and will no doubt give me another problem…

It may well be possible to get a spark eroder in there, that'd get enough of it out for you to clean the threads up. You'd need to drop the exhaust off the manifold so you're not pushing the waste into the CAT / DPF though.

I had my last FF done by LR some 3 years ago and the list hours was quoted as one hour?

and took them two hours, but still only charged for one.
My Indie quoted 2.5 hours.

I did the sensor on my present FF and it took me a couple of days, I think the trick is to soak it and get it hot, soak it, heat it, and so on and it will come undone but only if you undo it without strain to the side? a 1/2" deep socket will help to get it out it is a but doable

If it was a job I was doing, I'd cut off all the gubbins above the nut, heat with a small oxy-propane torch to keep the heat localised, get it cherry red, allow to cool and heat to cherry red again, then get a single hex impact socket (less chance of wear on the shoulders) on it with a 'T' bar using lots of side-to-side movement to free the threads, if it's not in the mood to move, then Plasma or spark eroder before anything is sheared off - less chance of damage to the manifold threads.

I just spoke to a Surrey LR main dealer who has quoted £840 (unclear of this is inc or ex VAT) but they also mentioned the worst case scenario would be if they had to take the engine out to replace the sensor.

Seems like they’re coped onto how nasty this job is.

I’m more tempted to give it a go myself now after that. Current: Range Rover L322 4.4tdv8, Porsche 911 (996) Carrera 2, BMW 535d Touring, Skoda Fabia, BMW S1000XR

Getting lots of penetrating oil onto it is definitely key, also a good fit six sided deep socket, not the special tool to loosen it, that’s just for fitting the new one.

Click image to enlarge

Davidmudley wrote:

I just spoke to a Surrey LR main dealer who has quoted £840 (unclear of this is inc or ex VAT) but they also mentioned the worst case scenario would be if they had to take the engine out to replace the sensor.

Seems like they’re coped onto how nasty this job is.

I’m more tempted to give it a go myself now after that.

Have you called a few independent specialists? Don’t forget we now have a forum sponsor close to you just nr Liphook on the A3. www.glenrands.co.uk
All LR trained technicians etc
Loan cars too Gone to a good home: 2011 4.4 TDV8 Vogue SE Buckingham Blue with Ivory and clear glass = "Rory"
2025MY Defender D350 90 in Silicon Silver on coils
1974 Series 3 Lightweight = "Millie"
Many, many other Landies over the years
My preferred specialist: www.glenrands.co.uk
--------------------------------------------------

you can save yourself a whole lot of grief, and get a guaranteed code clear, if you use my resistor fix, as detailed above. -been working fine for a few months now. the old nut, should it break, and become loose, it will allow an exhaust 'blow' which will have to be addressed.

total cost, about 20p!