ECU Remapping. (EGT DPF Add Blue Delete)

Francois J Kleyn

G-Wagen Club SA
Joined
Jul 14, 2022
Messages
36
Age
39
Location
Somerset West
Hello Guys.
I have had a bad experience having my car remapped and doing what is called an EGR and DPF delete. The purpose of this thread is to educate and not slam any ones businesses.

My car gave me a fault about 2 years ago and when I took it to MB they told me that there was an issue with dpf filter and or sensor. After doing a quick google ( my first mistake) it looked like the logical choice was to do a DPF & EGR delete. I took my car to a "reputable" company that had been doing this sort of thing for a long time and when I asked around got good feed back. When I got there I saw all kinds of high end cars. New Audi, WV, Mercedes and Toyota all having some kind of ecu remap done or EGR and DPF delete done. I thought id found the right place. They did the EGR & DPF delete and slight tune on the car. I drove the car away very happy as the fault code was gone and a bit more power under the hood.

A Year later my car started to smoke excessively to the point were you could not stand next to it and a horrible miss. I do not drive my G to much . Once a week to stretch the legs on a run to CPT and back home. 80 Km about. Car usually goes for service for the yearly service and not distance. So after 10000 km this problem arose. I took the car back to the company and thought they would sort it out no problem. after 2 weeks the car had not been fixed and I found out they had sent it MB to try restore the original MB ECU program(Flash). The reason for this is they could not read the injector values and some of the sensor values. This was my first red flag. Why could they not see these values with what they had done? While my car was at MB the company in question had there workshop flood. I went to go fetch my car from mb. So now my car was flashed with original MB software and when started went into limp mode and would turn off itself of 40 KM. So I drove the car back to the company that had done the DPF and EGR delete them and asked them to get the car running again. They got it running again. At what cost I cant tell you yet.

So far I have replaced the following to try fix these issue:
PCV Valve (saw oil build-up Infront of turbo)
Glow Plugs (waist of Time)
Injectors ( this Fixed a lot of the smoking but it still smokes.)

My latest discovery. I was speaking to another auto electrician and they told me what a lot of guys do is delete all alarm codes off the ECU so if there is any fault with any sensor it will not show up. This results in the ECU making adjustments with bad information. I took my car to the new auto electrician and sure enough my ECU had no Fault codes in it. They even deleted the Diesel temperature sensor fault code. I can also confirm this as I left my maff sensor disconnected and no faults came on before taking the car to him. The new auto Electrician is flashing MB Flash and going to try use the official codes to turn off the DPF. The EGR will most likely be reconnected.

In short be very careful guys.

One of the comity members Justin has some input on this topic and I will ask him to add to this post.
 

Justin JCA

G-Wagen Club SA
Joined
Jul 12, 2022
Messages
3
Location
Pietermaritzburg
Sorry I was cut short in finishing my response due to a long phone call.

If the egr is not closing 100% then it must be staying jammed open by soot or so - maybe needs a clean to allow 100%.

Next is an inherent issue with mapping is getting the vehicles to drive nicely with egr deletion. Usually one is meant to unplug the egr - but no matter what I have found, by unplugging it the vehicle does not drive as smoothly as one would expect and that I put down to my understanding that the egr works to assist in smooth gear changes etc as it takes the edge off boost, load etc when shifting.

Our approach is, delete but leave egr plugged in - and allow it to work passively in the background (it won't throw faults when and if it goes faulty - you will notice it driving a bit poorly if something has gone wrong - benefit of this is that at least you won't get a full on limp mode as if it were left un-deleted). This is the only component on the system that gets deleted in such a way... The rest is where true functionality is "deleted" - and this is purely because of the role the egr plays in the 350's for shifting etc. Profs are different and albeit not easy to delete properly - it is more possible, and blanking can be done to ensure it's non functional.

I have had one egr where it was a bit jammed up. Otherwise nothing else.

Check exhaust back pressure sensor reading on a diagnostic @idle it should be about 1bar then it's OK faulty sensors usually read 2bar and up to 5 bar when faulty at idle. This sensor is responsible for what the turbo actuator does - and in turn can give all sorts of surging issues etc.

In conclusion, egr valves themselves don't often give issues, something else might be at play...
 

Francois J Kleyn

G-Wagen Club SA
Joined
Jul 14, 2022
Messages
36
Age
39
Location
Somerset West
Some good news my car does not give the black smoke anymore and I have noticed a difference in how the engine runs. Seems smoother. The ECU flash was defiantly a big cause of this issue. I still have the smoke on start up and missing.
At the least some progress. Will be contacting another garage I have been told to go to by another member of this forum.
 

noyota

Member
Joined
Sep 2, 2022
Messages
223
Location
Kapstadt
One can fudge up your car for under 4 grand, as the BlueTEC gets "programmed" out at that price, followed by a free DPF + EGR delete. And everybody says how great this is, but on overseas forums, similar stories as the OP here show up. As this was part of my rather extensive due diligence before actually buying a low mileage G. Already, I have spoken to two owners of G350BT's about a decade ago, and both lost OM642 low mileage engines due to that oil supply issues. Replaced by M-B under maintenance plan, one of these was offered for sale with the famous Mercedes-Benz 2 year warranty on the new engine.

Then another forum member here lost an engine to Diesel in the oil sump, presumably misfed from regeneration of the DPF. I just parrot what others said, and have neither opinion nor any expertise.

Decades ago, I learned to keep things stock standard. And, after I ran main bearings 4x on my GM cars, I decided to avoid anything Chevrolet, Opel or rebadged Vauxhall .

My friend's beautiful low mileage 1986 W123 230E ran main bearings. While rebuilding the engine, we discovered there were no cotters fitted to the valve stems initially.

The bottom line is that nothing is risk-free. I have, after all, witnessed how my neighbour's visitors had to strip the wiring and rewire a RR Silver Shadow II on a Sunday afternoon. No family is above scandal, after all.

I decided to give my G dream a skip, to restructure how I work and be content with a rather cheap but simple Japanese solution, and not Diesel. I don't want a DPF on any of my vehicles but I also am not brave enough to rip the intestine out.

Thanks to all who share their joys and sorrows, as that helped me making an important decision, and saving me 1.5 bar. Cash don't grow on trees and I am a risk taker, but no gambler.
 

Francois J Kleyn

G-Wagen Club SA
Joined
Jul 14, 2022
Messages
36
Age
39
Location
Somerset West
So the good news is that my car in now 100%. Thank you to everyone that gave input.
The issue was the ECU Flash. The incorrect flash was put on the ECU and this is what has caused most of my issues. The om642 350D has the same block as the other om642 motors and that's basically were the similarities end. The 350D has different turbo, different intake and also different heads from what I can see. The company I found that helped me only does Mercedes Benz. The owner works on the cars and is very strait forward and to the point no time for chitchat. I wont take my car anywhere other than to him in the future.

For anyone that's going to do a DPF delete please be careful. I had someone call me and they suspect that the ECU flash they had caused them to loose a engine.

If I had to do this again I would try and keep the DPF. So I would remove the DPF as a complete unit and put in a pipe or maybe even a silencer in. This allows one to put it back if everything goes to hell.
Make sure they make a backup of the ECU before doing anything(maybe ask for the back). If they cant do this you are in the wrong place! A lot of guys do a backup of the ECU and send the file to a overseas company to rework for each car.

A DPF delete entails doing a EGR and Add Blue Delete . The Add Blue is part of the DPF system but the EGR needs to be deleted as the without the DPF the backpressure is incorrect. In short DPF EGR Add Blue all work together one cannot function without the other.

I have found a few Videos that show guys cleaning there DPF and wonder if this is the way I should have gone. I don't mind doing a clean every 80 000KM. Just cut out DPF and weld in some flanges. That way you can just bolt it out and run the clean. I see you even get additives that can do the clean also. There is an exception to this and that is if you are driving short distances your car can trigger a DPF cleaning every time you drive. Iv heard some horror stories.

My school fees on this one is around 50k I'm still going to send my old injectors for testing . I suspect that they are going to fine.
 
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