# Disable EGR



## Barry Allen (Apr 18, 2018)

Is there a way to easily disable the EGR on the Gen 2 diesel engines? Something simple like unplugging a connector to the EGR valve that leaves it closed?


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## quailallstar (Feb 16, 2018)

Barry Allen said:


> Is there a way to easily disable the EGR on the Gen 2 diesel engines? Something simple like unplugging a connector to the EGR valve that leaves it closed?


I don't think there are any solutions out yet. It would require an engine tune if you were to delete the EGR. 

I'm looking around the Opel forums to see if folks across the pond have any solutions yet. 

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## Barry Allen (Apr 18, 2018)

quailallstar said:


> It would require an engine tune if you were to delete the EGR.


I'm just wanting to do something like unplug the EGR valve if it defaults to the closed position. I'm willing to put up with a Check Engine Light for now, until an engine tune is available.


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## Taxman (Aug 10, 2017)

Barry Allen said:


> I'm just wanting to do something like unplug the EGR valve if it defaults to the closed position. I'm willing to put up with a Check Engine Light for now, until an engine tune is available.


But until you try it, you don't know if it's a CEL or a 'reduced power in 50 miles' warning.


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## Barry Allen (Apr 18, 2018)

Taxman said:


> But until you try it, you don't know if it's a CEL or a 'reduced power in 50 miles' warning.


I can wire in a switch to consistently reset it. A friend of mine has that on his Jeep Liberty CRD. It's a switch in the cabin where you leave the EGR enabled for about 30 seconds after starting the engine and the ECU apparently only checks EGR functioning right then. After that short time period you can turn the EGR off and drive the car with no CEL showing up.


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## Jacque8080 (Oct 31, 2017)

Why disable the EGR?


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## Barry Allen (Apr 18, 2018)

Jacque8080 said:


> Why disable the EGR?


Better fuel economy and to keep from gunking up the intake.


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## Diesel4Ever (May 30, 2018)

Barry Allen said:


> I'm just wanting to do something like unplug the EGR valve if it defaults to the closed position. I'm willing to put up with a Check Engine Light for now, until an engine tune is available.


I wouldn't do that.

I tried doing this with my TDI. Forced the valve closed with Ross Tech software. The ECU retarded the ignition timing and made it run like ****, lost about 10 MPGs.

You would need to re-map the fuel and boost to take advantage of the extra O2 in the clean airstream.


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## quailallstar (Feb 16, 2018)

Diesel4Ever said:


> I wouldn't do that.
> 
> I tried doing this with my TDI. Forced the valve closed with Ross Tech software. The ECU retarded the ignition timing and made it run like ****, lost about 10 MPGs.
> 
> You would need to re-map the fuel and boost to take advantage of the extra O2 in the clean airstream.


Oh how I miss Vagcom  

I'm wishful VW gets back into the TDI game stateside... Yes wishful thinking. 

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## Barry Allen (Apr 18, 2018)

Diesel4Ever said:


> I tried doing this with my TDI. Forced the valve closed with Ross Tech software. The ECU retarded the ignition timing and made it run like ****, lost about 10 MPGs.
> 
> You would need to re-map the fuel and boost to take advantage of the extra O2 in the clean airstream.


Ignition timing? You're using terms from spark ignition engines.

Diesel engines run O2 rich at all times of operation. EGR is used to reduce O2 content to avoid NOx production. A total elimination of EGR means the same amount of fuel is being injected (if you didn't change fueling) and there should be no change in operation other than avoiding your intake being sooted up with exhaust gas.

There has to be something else going on with your TDI tuning.


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## Diesel4Ever (May 30, 2018)

Barry Allen said:


> Ignition timing? You're using terms from spark ignition engines.
> 
> Diesel engines run O2 rich at all times of operation. EGR is used to reduce O2 content to avoid NOx production. A total elimination of EGR means the same amount of fuel is being injected (if you didn't change fueling) and there should be no change in operation other than avoiding your intake being sooted up with exhaust gas.
> 
> There has to be something else going on with your TDI tuning.


Sorry Barry, I mis-spelled injection timing, but spell check corrected it to ignition. 

Regardless of the spelling error you should know what I'm talking about. All modern diesel are common rail systems where fuel injection and duration is controlled by the ECU related to load and crank angle position.

On my TDI, I manipulating the EGR valve to closed position. As a result, the ECU adapted by retarding the *injection* timing. Not sure about duration. I can say that it ran like S--- until we restored the degree function of the EGR. After that it was back to normal.

The TDI ECU will react to a change in EGR flow and adjust timing, which is what happened. This is well known to most tuners, however, like you, I thought it could be easily changed to improve efficiency. Unfortunately, this was not the case.

These new diesels are not like the old ones where timing was controlled by the IP. The new Cruze diesel engine is more sophisticated than my TDI was, it even has VVT. So I'm sure you will also have a similar experience. The ECU will need to be re-tuned to operate w/out any EGR and de-fueled for you to take advantage of the extra O2.

That's the reason I do not recommend you do meddle with the EGR valve. I suggest you contact Green Diesel Engineering and ask them to create a ECO tune for this engine. If they get enough of a response, it may happen.


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## ParagonPCS (Jul 12, 2018)

Hi there,

I too am looking for a solution to this. Green Diesel Eng. seems to be the most hopeful promise. I've visited up there a few times already and brought it to their attention there is a market for that tune. My Dad own a '14 Ecodiesel by RAM. Hauls TT, Airstreams, Boats, Cars with it as a business. Has the EGR tune they offer for it, loves it, no trouble with it at all. 450k on the truck so far - guy's a madman. Moderates for https://www.ram1500diesel.com and loves all things Ecodiesel. He turned me on to the Cruze TD as an option for my business. Fingers crossed we get our version of the tune with a warranty on it sometime soon.


All The Best,

Gabriel


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## Diesel4Ever (May 30, 2018)

ParagonPCS said:


> Hi there,
> 
> I too am looking for a solution to this. Green Diesel Eng. seems to be the most hopeful promise. I've visited up there a few times already and brought it to their attention there is a market for that tune. My Dad own a '14 Ecodiesel by RAM. Hauls TT, Airstreams, Boats, Cars with it as a business. Has the EGR tune they offer for it, loves it, no trouble with it at all. 450k on the truck so far - guy's a madman. Moderates for https://www.ram1500diesel.com and loves all things Ecodiesel. He turned me on to the Cruze TD as an option for my business. Fingers crossed we get our version of the tune with a warranty on it sometime soon.
> 
> ...


I guess your dad got one of the few good Ram Ecodiesels. I wouldn’t buy one of those things for 50% off retail.

I created a post asking about an Eco tune for the Cruze 1.6L on the Green Diesel forum about a month ago. I suggest you guys create profiles and “pile on” to the thread, post “I’m in” or something so they can gauge interest.


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## firehawk618 (Feb 24, 2013)

Wait until HPTuners is compatible with our cars. Then let the mods begin.


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## GotDiesel? (Sep 9, 2013)

What's needed is to have a tune to set the EGR to a Dynamic operation = less of it, alot less.


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## Diesel4Ever (May 30, 2018)

GotDiesel? said:


> What's needed is to have a tune to set the EGR to a Dynamic operation = less of it, alot less.


1. Break ECU encryption.

2. Throttle EGR valve operation. 

3. R & D. Lean out fuel maps and boost curves for new parameters excluding the influence of EGR.

4. Alter DEF dosage using limits or forced values. Otherwise higher NOX values with cause DEF usage to be ecxessive and eventually damage the SCR.

You’re better off contacting the tuner I mentioned earlier who has the resources to do do all this stuff as it is beyond the capabilities of most people.


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## Barry Allen (Apr 18, 2018)

Diesel4Ever said:


> higher NOX values with cause DEF usage to be ecxessive and eventually damage the SCR


How does higher DEF usage ruin the catalyst?


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## Diesel4Ever (May 30, 2018)

Barry Allen said:


> Diesel4Ever said:
> 
> 
> > higher NOX values with cause DEF usage to be ecxessive and eventually damage the SCR
> ...


I was told excessive DEF usage would cause crystallization inside the catalyst and restrict flow.


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## MP81 (Jul 20, 2015)

Perhaps only if it's excessive related to the amount of exhaust flowing through it (and thus, NOx).

There are NOx sensors before and after the SCR that would adjust the amount of DEF in accordance to the NOx "content" of the exhaust gasses.


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## Diesel4Ever (May 30, 2018)

MP81 said:


> Perhaps only if it's excessive related to the amount of exhaust flowing through it (and thus, NOx).
> 
> There are NOx sensors before and after the SCR that would adjust the amount of DEF in accordance to the NOx "content" of the exhaust gasses.


Yes, but you fail to realize that by tuning the ECU and disabling EGR, NOx concentrations will increase substantially as you will have a leaner mixture and and more complete combustion. As a result of complete combustion, less soot is generated so the Regen time between DEF cleanings will increase.

You will not be able to treat the exhaust with the SCR so it’s best use forced values or disable it completely.


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## MP81 (Jul 20, 2015)

Pre-SCR NOx sensor would pick that up and use extra DEF to bring the post-SCR NOx reading down back to what it wants. Like I said before.


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## Diesel4Ever (May 30, 2018)

MP81 said:


> Pre-SCR NOx sensor would pick that up and use extra DEF to bring the post-SCR NOx reading down back to what it wants. Like I said before.



You’re assuming it can. It’s speculation. Nobody knows if it’s possible because the SCR was never designed as primary treatment for NOx, and at higher concentrations than it would ever see otherwise. It is a secondary treatment after EGR. Do you think GM would engineer the extra capacity to treat NOx at 300% or more of normal in the SCR? I seriously doubt that would be cost effective under current “value engineering” principals used in manufacturing.

You can contact GDE and ask get their input on What may be possible. You can also put pressure on them to develop a tune for the Cruze.


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