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2013 Forester 2.0D
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EGR will operate as usual, but because it will be blocked by the plate ECU will detect a missing portion of air from EGR and you will get error from time to time.

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Shouldn't you also progrram the ECU not to use the EGR any more?
At least that was the procedure back when I had my previous car (Alfa Romero 159 1.9 MJTD).
 

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2010 Forester Diesel 6sp Manual
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Shouldn't you also progrram the ECU not to use the EGR any more?
At least that was the procedure back when I had my previous car (Alfa Romero 159 1.9 MJTD).
There are 2 ways for reprogramming - one is to block EGR physically and delete (disable) EGR related DTC's, that way EGR will continue to work and car wont show CEL. And if you want, you can remove blanking plate and EGR will function normal, but you wont have any errors related to it, if something goes wrong.
2nd way is to disable EGR so that it stays closed all the time. That way it will still work during regens, but will be closed under normal driving.
 

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There are 2 ways for reprogramming - one is to block EGR physically and delete (disable) EGR related DTC's, that way EGR will continue to work and car wont show CEL. And if you want, you can remove blanking plate and EGR will function normal, but you wont have any errors related to it, if something goes wrong.
2nd way is to disable EGR so that it stays closed all the time. That way it will still work during regens, but will be closed under normal driving.
Ok, Thanks for clarifying. With my previous car I only had partially closed (programmatically) EGR so that it still worked but didnt open as much.
 

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There are 2 ways for reprogramming - one is to block EGR physically and delete (disable) EGR related DTC's, that way EGR will continue to work and car wont show CEL. And if you want, you can remove blanking plate and EGR will function normal, but you wont have any errors related to it, if something goes wrong.
2nd way is to disable EGR so that it stays closed all the time. That way it will still work during regens, but will be closed under normal driving.
Just to confirm. If you put the blind plate do you need to touch the ECU not to get errors on the dash? Is there any way of improving the way the EGR works without reprogramming the ECU? Thanks!!
 

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Just been on a 380km trip today on the motorway today (non-stopping). As I mentioned in the last few days, my car regens too often even in long motorway trips.
I attach 2 pics with graphs of the EGR, rpm, MAP, differential DFP, and soot. Please correct me if I am wrong in making the final conclusion:
  • soot builds when EGR is above 20
  • plus this happens when rpm drops (I was approaching the city)
  • when EGR is above 20 the DPF differential pressure sensor goes up
  • MAP (and MAF not shown in this graph) seem to measure fine as they increase with rpm
This backs up what some of you have discussed for long that the problem in this diesel engine is not just the DPF but it’s link with the EGR.
Next: I plan to clean my EGR and put the blind plate as first step.
 

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You are right, but in other words : egr stay permanently close after 2800rpm ( or close to this) - with all benefits you mention. You clearly see that soot acumulation was so low on high rpm compared when EGR was open because of low rpm . So another proof to close it. :) . Most intererestin discution for me will be the disadvantages on long term by doing this .
 

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Thanks Sorin 003. Yes, long term effects are important. Of note, I blocked the EGR of a previous ford focus tddi I had many years ago (no FAP at that time) and had no problems. It took more time the car to warm up and water temperature dropped earlier when not pressing the throttle. I sold the car with 300.000km (around 100.000 with EGR blocked) with no problems.
 

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2010 Forester Diesel 6MT
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Discussion Starter · #429 ·
Hi all, missed the past few days so let me throw some spanners in the works, given I started the thread in the first place.:)

This applies to my 2010 model

Note the following are my thoughts and opinions
- my current DPF is an aftermarket one and I believe it may be smaller than the norm
- my current DPF has been subject to bad city running and abuse to a soot which put it "off scale" and I susequently somehow managed to 'rescue' it. But permanent damage may have been done internally and it may not respond normally now - see below
- leaks in the induction piping after the MAF may also cause issues as it means the measured airflow is more than the inducted one under boost, leading to enrichment and soot production
- it may be my DPF diff pressure sensor is temp sensitive, or the DPF flow is now temp sensitive
- I may have induction leaks- I've felt the pipes for cracks and not noticed any, plus checked the visible (top) connectors. I'll need to pull bits off and check visually.

Note the following are all my observations / in my experience from monitoring with Torque Pro:
1) EGR closes during regen. This makes sense as you need as much air as possible to burn the diesel and raise the temp. EGR reduces available oxygen plus adds thermal mass through the inert /non-combustible gases, thereby reducing exhaust temp. However the throttle also closes which seems to be to control the fresh air flow
2) EGR isn't just used during cruise at temp, it's also used during warm-up to speed up warm-up.
3) EGR reduces my soot production- in fact reduces it when the soot level is high- by reducing the DPF differential pressure through reduced air induction. Hence suspicion of restricted DPF flow
4) Running at lower revs under gentle throttle extends my time between regens due to reduced MAF values and copious EGR.
5) Under coasting conditions, EGR is closed- this increases fresh air flow (due to no throttle)
6) Running any sort of boost esp without EGR (eg hard acccel) quickly grows the soot after the first ~50km after a regen
7) Soot level rises when the engine has been hot for some time- say 20 mins- and the DPF diff pressure is higher
8) When cold the soot level often decreases substantially and quickly with minimal DPF diff pressure. Again, some temp effect- not sure if the sensor, DPF itself, etc.
9) Yes in general the car has performed better in winter with regen distances. However in summer, if you can get the EGT over 400C and esp if you have one of those DPF cleaner additives in the tank, passive regen takes place and the soot level should decrease.
 

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Thank you for the thoughts, very interesting. I may need to try one of those DPF cleaners (i.e. liqui moly) and see how it works in long trips.
 

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This is nice proof that Subaru diesel likes winter I made DPF cleaning last autumn, 1st regeneration was forced at service after DPF cleaning. Since then only 2 active regenerations and more then 3000km from last one. I hope to have at least 600km at summer but I think that I will be happy if I will see something above 300km... I report back later at summer.


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2010 Forester Diesel 6sp Manual
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if I am not wrong EGR is closed during regens
You are not wrong. IIRC it opens when you coast so less fresh air comes in and cools the dpf. I should check that next regen.
If you put the blind plate do you need to touch the ECU not to get errors on the dash? Is there any way of improving the way the EGR works without reprogramming the ECU?
There will be errors without reprogramming the ecu.
 

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That’s absolutely crazy svkforester! Keep us informed! I wished mine worked like yours! I will have to force a regen on the motorway by reving the engine up and see if that improves subsequent regens. I had my dpf cleaned 3 weeks ago but not seen any improvement. They did not forced a regen afterwards though.
Cheers
 

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That’s absolutely crazy svkforester! Keep us informed! I wished mine worked like yours! I will have to force a regen on the motorway by reving the engine up and see if that improves subsequent regens. I had my dpf cleaned 3 weeks ago but not seen any improvement. They did not forced a regen afterwards though.
Cheers
After DPF cleaning ECU values has to be reset and 1 forced regeneration is needed for calibration. So if you made only cleaning then this could be your problem, probably...

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Thanks svkforester! I am going to find a garaje so they can force the regen and reset the values and see if that helps
 

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Discussion Starter · #436 ·
I can concur that after 'rescuing' my DPF from the depths of soot hell back to a manageable level I performed a forced regen to complete the job (which didn't take too long) and it behaved well for a period afterwards.
 

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I can concur that after 'rescuing' my DPF from the depths of soot hell back to a manageable level I performed a forced regen to complete the job (which didn't take too long) and it behaved well for a period afterwards.
So you did it driving on the motorway at above 3000rpm or something like that? How long for? If I go to the garage they will charge me 120-150 euros I guess.
 

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As far as I know there is a need of reset for DPF values after cleaning in ECU. So it has to be done in authorized service and 1st regeneration is for learning/adapting ECU. It can't be done by driving on motorway.

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So, what is the order? First they reset ECU and then force the regen? Vice versa? I don’t trust subaru garages in Spain, they have demonstrated little or no knowledge.
 

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From what i know the order is clean DPF (optional) , resset values - total ash, soot , attempt regen , regen- forced regen( which can be done with special tools and SSM - didn't heard to many ppl to have such tools or others and they did it by their own - just because is verry expensive - only license for SSM is like 5k-7k $/year. -) then oil change and resset dilution .
Do you heard something about Subaru Gamboa in Madrid ? Good or bad? They sell also Hyundai but also Subaru.
 
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