EGR Mod on my V9X

[peterLeo1]

Just some info for anyone planning to block their EGR on their V9X (550) motor.
I blocked mine about 5-6 months ago after talking with a specialist Diesel mechanic.
I mainly did it to reduce the soot going back through the engine and pickup some better economy and power.
To be honest I did not see any real improvement (maybe 0.5 LPHK) in economy and power delivery was a little better off the mark (however I do a fair bit of towing (Van 2.5T).
The Mod itself is pretty easy: Just made up a blacking plate from the gasket on the existing EGR pipe (which is under plastic engine cover, running from front to back of engine right in the middle, a steel pipe about 25mm round and has ribes almost all the way along it) out of 2mm alloy.
The first version of this plate had no hole, and I found after using car every day (without engine fault light on) for a week then received an engine fault light, it stayed on for about 3 days then went off for about 1 week before reappearing for another 2-3 days then off for another week then when came back on, stayed on permanently.
Note 1, I did no other mod to the car during this time, so was related to the EGR fault.
Note 2, when ever the engine light was up it did not allow me to SET the cruise control, it would come on but I could not set it to any speed (would flash when trying to set speed but the speed numbers would stay blank)

After about 2.5 months I decided to remove blanking plate and drill a 6mm hole in the centre of it, the engine fault light stayed up for the next 1-2 months. (so no change to performance or the fault light - it was still on and could not use cruse control.
I then read some where on the internet that the hole had to be at least 8mm in size, and of course made this mod (version 3) and would you believe within a few days of driving the Fault light went out, and has been fine for 1-2 months now.

Note, I never did any ECU resets in this time so let the car do all its own monitoring, and drove the car everyday with a mix of urban and country driving.

After removing the plate each time and drilling hole it was quite incredible how much soot had built up in that time. I am glad I am limiting this stuff going back through the intake.

Hope this helps others looking to do an EGR mod on their V9X.

 

[happy john]

Well said Peter,and a good write up. Seems the fault light is very random as to when it appears. So you remove the plate regularly to re drill the hole?.

 

[jjohn]

Id be interested to see if the aluminium corrodes.

 

[Old.Tony]

I'm a little concerned that it's an alloy plate. That it needs an 8mm hole to allow enough flow to be detected is also a bit of a surprise, obviously Nissan have been working on the sensor some more.

 

[peterLeo1]

Well said Peter,and a good write up. Seems the fault light is very random as to when it appears. So you remove the plate regularly to re drill the hole?.

Hi John,
Just to be clear, I have a 2012 D40 STX and don't plan to remove the blanking plate again, I was only removing it to drill the hole larger to find the point where I could limit the amount of egr gas getting through while still having no fault light all the time, so that I could continue using the cruise control.

Note the fault light did not seem random (when the EGR was completely blocked), it was almost exactly a week of no fault then 2 days of the fault, this cycle happened 3 times, I assume that while the light was on for the 2 days it must have done its own ECU reset of the fault to turn it off after 2 days. It was almost as if the engine knew how long I had travelled and would check the amount of gas getting through and once it sensed that after showing the light 3 times just stayed on, so smarter then the average ECU I suspect.

Also did not like the engine light being on all the time after that, for if you developed another fault you would not know cos the light is already up from the EGR mod.
I had read extensively on the web about what others were doing to still have the EGR blocked but also not have the fault light come up, and also consulted a good mate of mine who is a Diesel mechanic specialist and had done the same mods to many of his Nissan Patrols/Navaras.
I had read from one thread that somebody had to drill at least an 8 mm hole in his to ensure the fault light did not come/stay up, so hence why I was trying different size holes till I got one that let enough egr gas through to not trip the fault sensor, and this guy was right on the money, it had to be a 8mm hole for me as well.
I also read that an Alloy plate was fine, I have used a heat proof gasket goo to sandwich between the alloy and steel pipe, and each time I removed would replace the goo to ensure a good layer of sealant.

 

[BMGTZ]

so, other than less soot going through, do you think are other benefits? When you say " power delivery was a little better off the mark" Has there been a change to lag at say a stop sign?

 

[auzzie dubber]

does this mean that with the 8mm hole that soot ect is still getting thru and would this hole get blocked up over time? or can you get the ecu remapped so no fault would show

 

[Old.Tony]

does this mean that with the 8mm hole that soot ect is still getting thru and would this hole get blocked up over time? or can you get the ecu remapped so no fault would show

That's an excellent point. Over time, that hole could be reduced in size and with heat and pressure the sooty buildup could solidify.

Flashing the ECU is possible, although it's an expensive exercise to remove the EGR check. It's also possible that a Nissan dealer could update the ECU during a service and wipe the changes.

I do wonder though if it's possible (and here's a possible project for someone!) to bodge a circuit up so that if there's an input to the EGR valve (instruction to open) the circuit sends a "flow positive" signal back to the ECU. It'll require an oscilloscope to check the normal input and output so that the input can be properly detected and the output can be properly generated, but if this was done then you could just block the thing off and be done with worrying about it.

 

[auzzie dubber]

good idea ive heard that a reflash can delete the egr and dpf fault lights if both removed . i think i read about it thru ausamarok crispmods do heaps of reflashes on just about every thing

 

[peterLeo1]

so, other than less soot going through, do you think are other benefits? When you say " power delivery was a little better off the mark" Has there been a change to lag at say a stop sign?

I do not notice any Turbo Lag at all now, however I still get the delay in response from planting your foot, which is the typical "Drive by wire" delay, I got this same response from my previous Pathfinder as well. Sometimes when I want to duck out into flowing traffic their is definitely a delay (0.5-1 sec) in planting the foot, to car selecting gear and opening throttle valve. If I use auto sports mode, it seems to improve the delay.

 

[blackpete]

I have an stx550 and wanting to do do this mod along with dpf delete pipe.I have just had the egr replaced had 1 week of warranty left.EGRs cost about $800 + labour mine has only done 55000Kms and don't want to have that problem again.At least they worked out how to do it without taking the engine out.Has anyone thought of an egr cheater.They do sell them on ebay but couldn't find one for the V9X.

 

[Robski]

hmmm do our 550's have dpf? I thought not

Cheers Rob

 

[Old.Tony]

My Nissan V9X "Training" Manual states very clearly:

The V9X engine destined for the Australian market is not equipped with DPF.

Save yourself some cash - or better still, take it to Scottybobcat and have him build you some sliders.

 

[blackpete]

Hi all I am sure my 550 has a dpf its the big round thing under the floor near the drivers seat.
I have taken the bolts out of it and its not just and empty container.I spoke to Robert at
chip tuning in NSW and he said he had seen a few 550s that did not have one. It does not have the 7th injector or sensors front and back just plugs in the holes where they would go.

 

[Old.Tony]

Hi all I am sure my 550 has a dpf its the big round thing under the floor near the drivers seat.
I have taken the bolts out of it and its not just and empty container.I spoke to Robert at
chip tuning in NSW and he said he had seen a few 550s that did not have one. It does not have the 7th injector or sensors front and back just plugs in the holes where they would go.

It's actually a second CAT. Please don't ask me why you need two CATs. Directly copied from the V9X training manual (and I won't even change the line breaks I'm doing a pure cut and paste):

V9X EXHAUST SYSTEM
Exhaust System
There are 2 Oxidisation Catalysts in the Exhaust System of the V9X Engine. The 1st is directly after the
Turbo Charger unit. The 2nd is located downstream – underneath the drivers seat.
Further detail & precautions regarding the components shown right can be found in the ESM as follows;
B ENGINE > EX (Exhaust System)
NOTE:
A Diesel Particulate Filter (DPF) is not fitted to V9X engines destined for the Australian market

If you've got that manual, look on P34.

 

[blackpete]

Thanks for that info makes sense explains why nothing else connected to it. Doesn't seem there would be much gained by deleteing anything maybe just egr

 

[Old.Tony]

True. I'd be very, very wary of any company that offered to sell you a DPF delete for the V9X. But here's the next conundrum that I just thought of, and knowing how catalytic converters work is key to the question but not the answer.

Catalytic converters have certain elements, usually platinum, palladium and rhodium on a ceramic honeycomb core in them. Chemistry 101 - some specific chemical reactions require a catalyst, for example creating water from hydrogen and oxygen requires an spark or a flame. In the car, there are three compounds converted in the CAT - unburnt fuel is converted to water and carbon dioxide, carbon monoxide is coverted to carbon dioxide and nitrogen oxides are converted to nitrogen and oxygen.

The reaction has the catalyst - but needs a reductant to get the thing going. That reductant happens to be a hydrocarbon - and fuel is good enough. Squeeze a little diesel out and the reaction starts. This usually happens in the exhaust stroke, when the injectors are opened a little. In petrol cars, they do the same. In both, oxygen sensors in the exhaust (referred to as heated oxygen sensors, or HO2S) determine if there's enough oxygen in the exhaust to allow the reaction, and provide the ECU with a means of checking that it's working (by making minor fluctuations in the fuel input and looking for that pattern as a reduction in available oxygen in the exhaust).

So - here's the conundrum. How does the reductant get to the second CAT? It's all caught and burnt by the first. What feeds the second CAT?

Take care of your CAT, by the way. I did hear that there was a rise in thefts of catalytic converters for those metals (mostly for the platinum, I'd wager).

 

[peterLeo1]

Hi John,
Just to be clear, I have a 2012 D40 STX and don't plan to remove the blanking plate again, I was only removing it to drill the hole larger to find the point where I could limit the amount of egr gas getting through while still having no fault light all the time, so that I could continue using the cruise control.

Note the fault light did not seem random (when the EGR was completely blocked), it was almost exactly a week of no fault then 2 days of the fault, this cycle happened 3 times, I assume that while the light was on for the 2 days it must have done its own ECU reset of the fault to turn it off after 2 days. It was almost as if the engine knew how long I had travelled and would check the amount of gas getting through and once it sensed that after showing the light 3 times just stayed on, so smarter then the average ECU I suspect.

Also did not like the engine light being on all the time after that, for if you developed another fault you would not know cos the light is already up from the EGR mod.
I had read extensively on the web about what others were doing to still have the EGR blocked but also not have the fault light come up, and also consulted a good mate of mine who is a Diesel mechanic specialist and had done the same mods to many of his Nissan Patrols/Navaras.
I had read from one thread that somebody had to drill at least an 8 mm hole in his to ensure the fault light did not come/stay up, so hence why I was trying different size holes till I got one that let enough egr gas through to not trip the fault sensor, and this guy was right on the money, it had to be a 8mm hole for me as well.
I also read that an Alloy plate was fine, I have used a heat proof gasket goo to sandwich between the alloy and steel pipe, and each time I removed would replace the goo to ensure a good layer of sealant.

Just an Update, after a further 3 months of no Fault light I got another engine light come up (401) so the egr sensor was still not getting enough gas.
I have now removed the blanking plate all together, for I would prefer to have no engine light and access to my cruise control. Not sure I would recommend anybody with a V9X to use a Blanking plate even with a 8mm hole.

 

[Stewie]

EGR Mod

Hi All,
I've blanked off my EGR Valve but with a drilled hole (8mm) which I installed just after the 1,000km service, all been great until 10,500kms when I was driving and the ECU light illuminated and of course I couldn't enable cruise control which was annoying... but I knew this day was as the 8mm hole in blanking plate would carbon up.
Plugged in OBD2 scanner and Fault P0401 (Exhaust Gas Recirculation Flow Insufficient Detected) so I then removed the EGR blanking plate and cleaned, the 8mm hole was reduced in size from the carbon and was now around 6mm. So I cleaned this up and re-installed.
I also noticed that there was oil sludge film covering the underside of EGR Valve blanking plate and internally within inlet manifold so I guess this is a combination of Exhaust gases and oil from the PCV valve which I guess my next mod to be to install a catch can.
Anyway back to the EGR valve's blanking plate which will no doubt flag another P0401 code and require removing and cleaning every 10,000kms, so I'm looking to a more permanent solution this being ECU Tune but this has problems and can be over written by Nissan, is there another way by tricking the Delta P sensor?
The information on the V9X engine is some what limited and does anyone have schematic's or Engine / EGR Valve diagrams which I can look to tricking this sensor?
By the way the Car build date in Nov 2012 and the ECU looks to have the latest firmware as I have read that straight after you shut off engine the ERG Valve flaps a number of times which its does.


Regards Stewie

 

[Old.Tony]

If I was going to do anything, I'd see what the expected response graph for the EGR flow sensor was. I'd imagine it would be something like (assuming the return signal is a voltage from 0 to 5V, 0 indicating no flow and 5V indicating max flow) the voltage multiplied by 1000 = rpm (except idle and full throttle). So idle = 0V, 1000rpm = 1V, 1500rpm = 1.5V, 2000rpm = 2V etc. Once I knew that, I could tap into the tachometer feed and return that signal (roughly, have to look at the TPS to return 0V for throttle-off and throttle-max too) back to the EGR flow sensor.

Malicious might have an idea on playing with this too, or maybe auggie who's tinkered with DPF sensor replacements.