Looking at the DPF regen requirements you would need to sustain over 2500 revs for 20 minutes or so and a speed of over 30mph.
During normal driving even on motorway, this would not be achieved. Unless forced with command shift. I wonder how the vehicle is supposed to automatically carry out a regen?

Update after my previous post Empire tuning haver now got back to me so will correspond and try to come to some arrangement , Aviator I'm afraid your info on the regen process is flawed , it will happily regen and much lower revs but is tied in to speed , if amber light comes on it will regen at around 30mph and continue to regen even at idle when stopped in traffic , watched it happen on gap whilst monitoring soot levels , a good steady run of over 50mph on the motorway will happily start and complete a regen so trundling along at 60/70 is fine , I've found the cruise control can cause issues of quick soot build up (especially when towing) as it increases the throttle too slowly and for too long with the car locked in 8th so overfuels rather than kicking down and getting the speed up , I'm sorry to say but the CC is terrible at holding a steady speed on up and down roads (only slight inclines) compared to D2 and D3.
Matthew

I took it on a long drive down the M4 this evening. I held the revs at 3000 and speed at 70mph. The soot level actually started to increase! Even with dynamic regeneration engaged. After 30 minutes it was getting slowly worse so I switched it back in D (drive) and then it started to drop soot levels until
About 3g. Appears online info about keeping revs high etc is incorrect as you state.

Was this an active regen (started by the car) or did you do a forced regen via the gap iid, Aviator?

I find with mine that soot mass does seem to be dictated mostly by engine load. If I'm going up a hill or giving it some beans then it tends to increase, whereas if I drive around gently the soot mass tends to decrease after it's warmed up.

After just over 300 miles if gone from about 12g to 17g of soot, with a mixture of driving. Sometimes it increases significantly quite quickly, other times it seems to reduce quickly without being clear as to why.

I tried High revs driving down the motorway which only made it worse, so I forced a regen and continued with high revs, which only increased the soot level. It only started to decrease when I switched gears back to D and the revs dropped to about 1500.

While i've been monitoring mine i found the best way to increase soot levels is heavy throttle and high revs , steady cruising in D seems to be the trick and hoofing it is the worst , monitored it back down the A1 from scotch corner to Bramham turn off and it stayed at a steady 13.5 g just about all the way (tuggin 1.5t of tin tent so 60 ish and 1200rpm in 8th) , once i got off A1 and started fighting round Leeds to get home it went up n up till it started to regen in stop start traffic at about 24/25g, continued dropping even when stopped at lights right back down to around 7g then started rising again, by this time i was home . So it does work most of the time .

Thanks Aviator, that's very interesting to know.

I'm curious as to what the active regen behaviour is like with the EGR delete. I've only had the initial one which was immediately after the remap, and that didn't go as smoothly it used to.

That quite similar to what I see then I suppose Matt. With the only difference being that after the EGR delete I find that after 20 mins or so of driving, if I go gently the soot mass decreases rather than being static or very slow to increase.

Sometimes I wonder if the behaviour post EGR delete is how other cars function. I have friends that drive diesels and half of them have never heard of a DPF.

https://www.fullfatrr.com/forum/topic48068.html?highlight=dpf

Read this. We compiled that over a number of years. The advice and analytics are definitive and included input from the original L322 design team as well as some other very, very experienced individuals. Everything you need is in there.


. 2012 L322 4.4 TDV8 AB low mileage - a peach
1986 V8 Defender 90 County ex-Swiss Army - Red everything....

My preferred Independent: Roy Hardy. R & B AUTOS LTD, 20 Brook Road, Wimborne, Dorset, BH21 2BH 07500 866775‬ (Ex LR Chief Technician)

I’ve gone through that entire thread nearly twice now, so I’m probably as familiar with it as anyone could be without having contributed.

The reason I’m posting in this thread is that my car’s DPF behaviour has changed dramatically since the EGR delete.

Before the delete, regens were happening roughly every 60–100 miles. I’d plan my drives carefully to hold a steady throttle and fuel input once an active regen began, even if I wasn’t always at high speeds. This let me consistently bring soot mass down from about 20g to 6g. On one occasion, I even got a yellow warning during a 10‑minute drive to the motorway — and without the GAP tool, I’m sure I’d have seen a red warning more than once. Regardless of the types of journeys I did, soot kept building, and I constantly had a P040D DTC. From what I’ve read, that fault may cause the EGR cooler bypass to remain in a default cooling state due to inaccurate temperature readings, though I never found a definitive answer.

For context, I did notice some oil and soot on the plastic elbow from the IC hose, but it didn’t look as bad as some pictures I’ve seen. I did the O‑ring mod, which seems to have helped keep the mess at bay. About two years ago, the previous owner had the NS inlet manifold and injectors replaced, along with the intake donut and four hoses. I’ve also cleaned the MAP and MAF sensors, so short of a high pressure smoke test I'm fairly confident there wasn't a boost leak contributing to the soot mass.

Since the EGR delete, I’ve driven about 300 miles. The soot mass has gone from 11g to 17g, fluctuating with driving style. Interestingly, I’ve found that soot mass can actually decrease at relatively low exhaust temperatures (<200°C) and low speeds (20–30 mph) when driving gently for over 15 minutes — something I didn’t expect.

Most importantly, I don’t think I’d have understood this behaviour without the EGR delete. If anyone else is experiencing similar issues, hopefully this sheds some light. Ideally, I’d prefer the car to be completely stock, but constant regens didn’t seem normal, and replacing the EGR temperature sensor didn’t seem like a viable fix. My indy wasn’t confident it would resolve the DPF issues and was hesitant to attempt it due to the risk of losing the sensor.

My day job is in IT, and most of my career has been spent solving complex problems, often requiring a lot of learning beyond what I know at the time. So, it’s unlikely I’ll feel satisfied until I get a complete answer here — and I don’t feel like the linked thread got me there completely.

During the winter when ambient air is <5deg or thereabouts my regens were often 500miles apart and in summer they can be as little as 60 miles apart ( this is logging on constant M-Way cruising at 70mph). This is directly related to how much the EGR valve opens which is linked to the intake air temp. I would like to have an EGR mod that just reduced it's opening rather than a delete as I think come winter you will get extended warmup times. Have you noticed any drivability or mpg changes ? 2012 TDV8 Vogue (L322)

I've definitely noticed some mpg changes. At some point I prior to the egr delete I must have reset the trip computer without realising, and at that point it was about 22mpg over the past 500 miles, with probably about 150 or so of those post EGR delete, with a mixture of driving. When I reset it after that I was getting 30+ with town driving.

Drivability is better, but it's not straightforward. The throttle response can vary a lot as it seems to adapt, from what I can tell. I'd been getting a great throttle response for a while, but over the weekend I was taking a look under the bonnet with my father and we were revving the car a fair bit whilst it was stationary. The next time I drove the car it felt very sluggish initially, but then as I was putting my foot down more often it seemed to drive better after a few minutes again. Overall it doesn't hesitate anymore, but as I say it can sometimes feel sluggish or require a harder throttle press to move. I've had periods of time where the car hasn't been driven for a few days and it still maintains the lighter presses, so I presume something changed when I revved it whilst stationary.

The ambient temperature is very interesting. I've had the car since January 2025 and pretty much always checked the soot mass. I definitely noticed that it didn't increase as much in the colder months when I first got it.

I too would like a way to control the EGR, or at least have the option to switch between maps more easily. From what I understand if your ECU has been unlocked on a bench then there are some tools that will allow switching maps via an OBD tool, but I was hesitant to regularly flash the ECU, especially via a less direct method such as OBD.

Try resetting the accelerator by pressing it to the floor with the ignition off and then turn on the ignition and hold for a minute then shut down and release it. 2012 TDV8 Vogue (L322)

Had a chance to try the TPS reset today and have to say thanks, as that worked a treat. Only concern now is that I have to be careful to not speed.

Had to take the wife out to get some bits this morning and it only take 20 minutes for us to get to IKEA. As the ambient temperature was a little cooler today (11c) I definitely noticed that the engine took longer to warm up, and as a result there was an increase in soot mass that was much more noticeable than normal when the ambient temperature is higher. However, when I got a chance to drive on the motorway and get the engine temps up the soot mass started decreasing again, and then driving at slower speeds with the warmer engine I observed the usual minor decrease in soot mass.

I have to say I agree that ambient temps make a difference. It would be ideal if the EGR could be used to help with that initial warm up on colder days, but then shutdown once the temps were sufficient to reduce soot build up, and even open again once the temps could be reduced without increasing the soot mass too greatly. I don't know if getting the sensor causing the P040D-00 code would potentially provide that, but as I mentioned my Indy was concern about it breaking off and that's put me off. He used to work for RoverTune and from what I've read they were one of the first places to offer that fix, so I assume he's got some experience there.

There is a place about 20 mins from me that does Alive tuning remaps and I have considered speaking to them. I suspect it would cost a fair bit for a remap that could use the EGR as described (if it's even possible). I'm tempted to enquire regardless as the remap I currently have from a general remapper is a stage 1 and every time I shutoff the engine I can hear what I assume is compressor surge, presumably from the higher boost level at idle. From what I understand this doesn't always cause problems, but I'm also not looking to shorten the life of the turbo. I don't think there's much benefit to a stage 1 vs more of an economy map + EGR delete. Don't know if anyone has any thoughts?

I think the compressor surge noise is actually because the EGR valve is closed? I believe the pressure would normally escape through there on shutdown and now it cannot so leaves wherever it can. Just a thought?

I did wonder if that was the case initially, perhaps I read something along those lines. I have a blanking plate installed so I could remove that and see if there is a difference as the EGR valve doesn't close completely when commanded at 0