And is it best to get genuine?

Please stop forcing regens when the car's onboard ECU is managing it appropriately and not throwing any error codes. It's un-necessary and will only cause problems elsewhere.

The car's computer and DPF management system is acting as it should and producing an amber alert prompting you to drive above 50mph for a sustained period for it to do what it needs to do. When my vehicle was used for short trips around the city, the amber alert came up occasionally and all it needed was taking to the motorway for a 20 mile run - quite a nice thing to do on a summer's evening.

The red alert on the driver display is often caused by an intake leak and the DPF is the symptom, not the cause (a danger of using diagnostic kit); even then, this is often long preceded by the red "restricted performance" message on acceleration and produces no need to fiddle with the DPF. The intake leaks are well documented on this forum and easily fixed on the driveway with basic tools. Once those are ruled out, only then should a DPF regen be forced.

The P040D error is unlikely to cause any problems in the medium term.

The faulty sensor is likely to be the one shown below (LR022904), however there are multiple on the exhaust system, so you will need to confirm which one.

 2015 Range Rover Autobiography 4.4 SDV8

My soot count is increasing I’ve been told it can be the p040d fault causing it

Is part 22904 temp sensor on exhaust?

Yes. It's in the exhaust and a to replace hence why I said take it to a specialist
https://www.fullfatrr.com/forum/topic50202.html 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
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Craig5 wrote:

My soot count is increasing I’ve been told it can be the p040d fault causing it

I've heard this can have an impact but I'd be first looking at the 4 plenum intake hoses and the intercooler-throttle body BIG hose for any splits.
It needs a pro on it IMHO  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
--------------------------------------------------

Hi dr rob my only issue is will it get to the garage before it turns red from amber with the soot count increasing

The soot count will increase until such time the onboard computer decides it's time to perform a regen.

You can continue using the vehicle normally. What you have reported doesn't sound like there's a big issue. To extinguish the amber alert, you need to take it on a run.

When you have a spare few hours, take the various hoses off as in the article Rob linked and have a good inspection as well as squeeze for any splits. This is a good thing to do twice a year anyway. 2015 Range Rover Autobiography 4.4 SDV8

I have taken it on motorway today and amber light is now off

It's working. You can drive yourself nuts with it
Check 1) it has no intake leaks and 2) don't use it for too many short journeys. This applies for any car with a DPF. They like long runs.
Enjoy 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
--------------------------------------------------

I’ve noticed when it looks like my car is doing a regen it only seems to drop about 3-4 then stops that seems ok? My soot at moment is 11.5

I’ve just did some logging on my gap tool exhaust temp sensor bank 1 and bank 3 only changed temps with different driving speeds but sensor 2 would read say 285 then split second would got to 100 then back to 285 then say 135 for split second then back to 285 is that normal? do the temp sensors control the regen at all?

All connected in terms of feedback etc 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
--------------------------------------------------

I don’t understand your reply sorry

Craig5 wrote:

I’ve just did some logging on my gap tool exhaust temp sensor bank 1 and bank 3 only changed temps with different driving speeds but sensor 2 would read say 285 then split second would got to 100 then back to 285 then say 135 for split second then back to 285 is that normal? do the temp sensors control the regen at all?