Navara 2010 2.5 diesel fuel consumption

[Old.Tony]

Could you put a ECU from a 2007 auto without DPF into a 2008-2010 auto with DPF if the DPF had been deleted? recon it would work?

The ECU controls more than just the engine, but the actual management of the other functions may be controlled by other modules like the Body Control Module, Transmission Control Module etc.

No guarantee that the things will actually connect and if they do, the pinouts could have changed as well. We don't know how many little changes Nissan have made - and all you'd need to do is connect a plug that had one line as a 12V source where the ECU was expecting a 0.4-0.8V return value to kill the thing fast.

There may be a means of fooling the system though. Keep your eyes open for news about it.

 

[Chip Tuning]

WISH TO EXPLAIN FURTHER CAUSE WE'RE GETTING ASKED QUESTIONS.

The O2 Sensor is actually there to help measure the Performance of the DPF, if it were for fuel trim readings it would be pre & post Cat like the Petrol vehicles do. This is why when removing the Factory CAT the D40 does burns more frequently even with the DPF removed. It does not trigger the burn due to the Temp or Pressure sensor but due to the O2 level.

We have proven this a few times:
Remove DPF no issue.
Remove DPF & Factory Cat & use a High Flow Cat you STILL trigger very frequent burns & vehicle becomes engulfed in white smoke.

If the sensor is faulty, then it will try to do regens even when not needed.

Thats what we have found.

Hope this helps.

 

[Old.Tony]

So - Gus - we're probably on the right track.

 

[Bosshog]

So - Gus - we're probably on the right track.

I knew it!

Can't get to it this week (or weekend) but next week I'll be pulling the DPF back out and then wiring up one of those Potentiothingys and then crossing my fingers!

 

[apcconstructions]

OK, had the 10,000km service and as i thought they could not find anything wrong with the sensor and did a full diagnostic check and believe that everything should be fine. I spoke to the "Head" mechanic and he had a blank look on his face as he has no idea on how the sensors interact with the ECM. Once I advised the dealer that I have a 2006 auto Navara which is doing 10.5L100km and using nearly 50% less fuel did they contact the NIssan Tech Line. Nissan Australia has asked me to fill with BP Ultimate and write down the odometer for the next three tanks. I am also filling up my 2006 auto Navara at the same petrol station and will record the odometer as well. My nissan dealer says that if Nissan authorises it they will replace the fuel rail as sometimes the fuel rail sensor relief valve keeps the pressure too high which means more fuel injected with every squirt.

My dealer said that this is what they have done with a few of the cars with high fuel consumption.

I am also going to see if I can talk to a Nissan Tech on "nissans" purpose for the O2 sensor otherwise we are all flying blind here!! Does anyone know where I can get my hands on a 2010 workshop manual??


Will report back!!

 

[westy350]

Its seems that the dump pipe and cat on the DPF model d40's are different to the one's without the DPF maybe that is causing the restriction and higher fuel consumption. But the only way to remove that CAT is to trick that oxygen sensor that the cat is still there Bosshog is going to have a crack to tricking the sensor this week so we will have to wait and see how he goes.

 

[Bosshog]

I have hollowed out my DPF( (drill bit and star picket) and it made bugger all difference maybe gained 1L/100km.

I got the same improvement by simply removing it completely.

In response to CHIP IT - I'm not sure how the O2 sensor is related to the DPF burn. The DPF burn is triggered by a difference in air pressure before and after the particle filter. When the pressure is higher at the front of the dpf than the rear it is obviously blocking up and this triggers the burn. There is also a temp sensor before and after which monitors the temp during the burn cycle.

Whilst this is correct, the O2 sensor alone can trigger a burn - which will happen when you remove the factory dump pipe/cat as well as the DPF.

and the only thing a O2 sensor can do is tell the ECM if it is running rich or lean - It can't say how rich or how lean the mix is so I don't know how this is any help during the DPF burn cycle or what function an O2(air fuel ratio) sensor would serve in regards to the the DPF. During a burn there would be no reason to monitor the DPF for a perfect air fuel ratio mix which is essentially all this sensor can do.

I would be interested in an alternative explanation on its function.

Gee I wish I knew!

OK, had the 10,000km service and as i thought they could not find anything wrong with the sensor and did a full diagnostic check and believe that everything should be fine. I spoke to the "Head" mechanic and he had a blank look on his face as he has no idea on how the sensors interact with the ECM. Once I advised the dealer that I have a 2006 auto Navara which is doing 10.5L100km and using nearly 50% less fuel did they contact the NIssan Tech Line. Nissan Australia has asked me to fill with BP Ultimate and write down the odometer for the next three tanks. I am also filling up my 2006 auto Navara at the same petrol station and will record the odometer as well. My nissan dealer says that if Nissan authorises it they will replace the fuel rail as sometimes the fuel rail sensor relief valve keeps the pressure too high which means more fuel injected with every squirt.

My dealer said that this is what they have done with a few of the cars with high fuel consumption.

I am also going to see if I can talk to a Nissan Tech on "nissans" purpose for the O2 sensor otherwise we are all flying blind here!! Does anyone know where I can get my hands on a 2010 workshop manual??


Will report back!!

You will simply prove that an auto with a DPF installed uses a shit load more diesel than one that does not. Changing the fuel rail will not make any difference (but lets hope that I am wrong) because the ECU will still want to inject diesel into the exhaust to complete a burn periodically regardless of a new rail or not.

I only use BP ultimate (bush trips excepted) and my fuel consumption is still high.

Good luck

 

[burgo]

OK, had the 10,000km service and as i thought they could not find anything wrong with the sensor and did a full diagnostic check and believe that everything should be fine. I spoke to the "Head" mechanic and he had a blank look on his face as he has no idea on how the sensors interact with the ECM. Once I advised the dealer that I have a 2006 auto Navara which is doing 10.5L100km and using nearly 50% less fuel did they contact the NIssan Tech Line. Nissan Australia has asked me to fill with BP Ultimate and write down the odometer for the next three tanks. I am also filling up my 2006 auto Navara at the same petrol station and will record the odometer as well. My nissan dealer says that if Nissan authorises it they will replace the fuel rail as sometimes the fuel rail sensor relief valve keeps the pressure too high which means more fuel injected with every squirt.

My dealer said that this is what they have done with a few of the cars with high fuel consumption.

I am also going to see if I can talk to a Nissan Tech on "nissans" purpose for the O2 sensor otherwise we are all flying blind here!! Does anyone know where I can get my hands on a 2010 workshop manual??


Will report back!!

Has anyone considerer that this device may be a NOX sensor and not a O2 sensor. This would be consistent with some designs for emission monitoring and control.
Good luck with Nissan tech's as I don't think they know??
Rgd's

 

[Bosshog]

Has anyone considerer that this device may be a NOX sensor and not a O2 sensor. This would be consistent with some designs for emission monitoring and control.
Good luck with Nissan tech's as I don't think they know??
Rgd's

Thats what I always thought it was, but others called it an O2 sensor so I just been going along with em. Whatever gas it measures - its the root of our problems.

 

[Bosshog]

OK lets get this party started...

Here is my delete pipe

Here is a close up of the front end of the pipe. I have always assumed that A is pointing to where the front temperature sensor goes in - Can someone confirm that please. The front pressure sensor is just forward of that sensor (i.e. on the other side of the flange).

And here is the rear of the pipe with three holes. The lower one is the rear pressure sensor. I am assuming B is the O2 sensor - Can someone confirm that please. C is the rear temperature sensor - Can someone also confirm that too please. My assumptions are based on the size and similiarity of the front and rear fittings and probes with the temp sensors. Both B and C run back to electrical connectors attached to a metal flange adjacent the DPF/Delete pipe.

Once we agree on which one is the O2 sensor, then my plan is to unclip it back at the electrical connector and attached the resistor using the same plug. This eliminates stripping wiring back and ensures a connection that won't come loose.

In the meantime, I got to 'half remove' my long range fuel tank, pull off the rear bash plate and install the delete pipe. Then reinstall everything. Might leave off the bash plate until I sort this one way or another.

Thoughts welcomed.

BH

 

[Bosshog]

And here is the how the wiring and electrical connectors for B and C look.

 

[apcconstructions]

And here is the how the wiring and electrical connectors for B and C look.

B is the O2 sensor it will have 4 wires (white is the sensor ground and blue is the sensor signal) and two black which is the heating wires for the element(one is ground one is 12v)
C is the temp sensor

From what I found out below messing with the O2 sensor probably won't make a difference - If you install a resister that lowers the voltage reading it may cause the ECM to think it is running lean and increase fueling to get the exhaust rich causing white smoke - actually if you do this let us know if white smoke comes out and this might help to confirm my theory based on what the Chip It guys were seeing!!

You may have to drive around the block for a while as the sensor won;t send back any readings until it reaches 300 degC. My sensor didn't give any readings until i drove the car for about 5 mins on the freeway! At idle nothing

 

[apcconstructions]

Thats what I always thought it was, but others called it an O2 sensor so I just been going along with em. Whatever gas it measures - its the root of our problems.

Found this site which may help everyone to understand what is going on with regards to the emission control and dpf etc. Take your time reading it!!

http://www.meca.org/cs/root/emission_control_technology/offroad_diesel_equipment

From what I can understand diesel engines normally run leaner than petrol engines which is good for control of co and hydrocarbon emissions but causes a problem for NOX emissions. In order for the catalytic converter to convert nox emissions it needs to be done in an oxygen depleted environment. It appears that nissan have had to run the engine rich in order for the nox emissions to be converted by the cat. rich = oxygen depleted environment

I do believe that the sensor we are all talking about "is" an O2 sensor which measures whether the engine is rich or lean for the purpose of the catalytic converter and not as I first thought to trim up the fuel map. I'm now guessing that the ECM wants the reading to be above .45v (rich mixture) in order to keep the nox emissions down.That is what i am seeing on my NAV.
This may explain that when the chip it guys removed the cat lots of white smoke was coming out the exhaust. The cat was no longer reacting the co gases thus confusing the sensor into thinking it was running really lean - therefore the ECM was chucking in more fuel on exhaust stroke to try and run rich and hence white smoke ( white smoke usually means unburnt fuel - those who have ever mucked around with the old diesel engine will have noted that if you advanced the shit out the timing ie fuel is getting injected too late it just comes out the exhaust as white smoke)

I think that Nissan would be running the same fuel map as the pre 2.5 euro emission engines without the cat but in order to get a rich mixture to get rid of O2 in exhaust they would most likely chuck an extra squirt in the exhaust stroke =bad fuel economy.

If this is the case there is no way of tricking the ECM by playing around with air flow sensor values etc as that would only serve to mess around with the original fuel map and the ECM would still chuck the extra squirt on top.

I guess the only way is an aftermarket chip or module that would be reprogrammed to ignore the extra squirt pulse sent to the injector???

Any thoughts on this theory???

F.ck you Nissan you stupid F.cK F.ck

 

[Old.Tony]

Sounds plausible. Injecting fuel on the exhaust stroke is useless in terms of power delivery because it's basically fuel that's being dumped. It may well achieve the goal - it does appear as you say that the exhaust needs to be oxygen-depleted in order for the NOx to be altered to N2.

If this is the case, the discussions that Gus and I have had may prove fruitful for the O2 sensor. The extra exhaust squirt for the CAT is an issue that we can't deal with as easily.

I'm guessing that the chip manufacturers would be hesitant to remove this as it's part of the vehicle's emission control system, although from a sale point of view, they can offer it as an "off-road use only" after-market device and then it's up to us to deal with it properly. I think Robert from Chip-It would need to give us advice on that - in order to remove (ignore) the exhaust-stroke-injection, the chip would have to KNOW that the injector is being asked to open in the exhaust stroke, so the chip would have to know what the current crank angle is in order to know to ignore it and leave the injector closed.

I don't know if Chip-It would be willing to do that - whether optionally or otherwise - unless they had a guarantee of a certain number of orders. They may also want a test vehicle for it and while I'm happy to experiment with stuff normally, I think Robert & crew are a little too far away from Newcastle (I honestly don't remember where they are, I thought they were in Qld). I guess this is where we invite Robert to give us some feedback.

I'd also be interested in Robert's feedback on the O2 sensor and the enrichment of the exhaust stream and whether or not their chip would modify this remapping to remove the effect of the O2 sensor altogether.

On our own - the best we could do is fool the O2 sensor, but getting rid of that exhaust stroke squeeze would mean reprogramming the ECM and that's not something I'd want to try.

 

[apcconstructions]

Sounds plausible. Injecting fuel on the exhaust stroke is useless in terms of power delivery because it's basically fuel that's being dumped. It may well achieve the goal - it does appear as you say that the exhaust needs to be oxygen-depleted in order for the NOx to be altered to N2.

If this is the case, the discussions that Gus and I have had may prove fruitful for the O2 sensor. The extra exhaust squirt for the CAT is an issue that we can't deal with as easily.

I'm guessing that the chip manufacturers would be hesitant to remove this as it's part of the vehicle's emission control system, although from a sale point of view, they can offer it as an "off-road use only" after-market device and then it's up to us to deal with it properly. I think Robert from Chip-It would need to give us advice on that - in order to remove (ignore) the exhaust-stroke-injection, the chip would have to KNOW that the injector is being asked to open in the exhaust stroke, so the chip would have to know what the current crank angle is in order to know to ignore it and leave the injector closed.

I don't know if Chip-It would be willing to do that - whether optionally or otherwise - unless they had a guarantee of a certain number of orders. They may also want a test vehicle for it and while I'm happy to experiment with stuff normally, I think Robert & crew are a little too far away from Newcastle (I honestly don't remember where they are, I thought they were in Qld). I guess this is where we invite Robert to give us some feedback.

I'd also be interested in Robert's feedback on the O2 sensor and the enrichment of the exhaust stream and whether or not their chip would modify this remapping to remove the effect of the O2 sensor altogether.

On our own - the best we could do is fool the O2 sensor, but getting rid of that exhaust stroke squeeze would mean reprogramming the ECM and that's not something I'd want to try.

Just something to try in terms of elimination - Maybe unplug the O2 sensor and drive for 100km and check fuel usage. By unplugging the O2 sensor the car still operates fine (seems to run on default fuel map) .It does throw an internal fault code ( can be plugged back in and codes wiped before service) but if the computer doesn't get a reading back from the sensor it just disregards it and maybe when the ECM operates without the sensor it won't chuck the extra fuel in as it can't monitor what it is doing via the exhaust gases???

Harmless experiment to try!!

 

[Old.Tony]

Just something to try in terms of elimination - Maybe unplug the O2 sensor and drive for 100km and check fuel usage. By unplugging the O2 sensor the car still operates fine (seems to run on default fuel map) .It does throw an internal fault code ( can be plugged back in and codes wiped before service) but if the computer doesn't get a reading back from the sensor it just disregards it and maybe when the ECM operates without the sensor it won't chuck the extra fuel in as it can't monitor what it is doing via the exhaust gases???

Harmless experiment to try!!

With your incredibly simple and as-yet overlooked idea in mind (and I'm thinking to myself "why didn't I think of that") I decided to look for the sensor values for the O2 sensors.

Houston, we have a problem.

The ECM doesn't just monitor the return values. If it did, we'd be just fine - 0V means a lean running motor, 1V means a rich-running motor (yes, that's ONE VOLT, not 12V with an idiot typist missing the '2').

Unfortunately for us, the sensor's response rate to changes is monitored. The ECM will send a pulse to the sensor and the sensor has to respond within a given time, or it is considered faulty and the ECM decides to throw a fault and go back to default mode. Shit, shit and shit.

I think we can probably discount this test, since the ECM is so adamant that the sensor not only has to be there, it has to respond within a given time frame, so a resistor just won't do the job either - sorry about that Gus, the experiment is off!

I wonder if ChipIt could advise whether they have - or could have - a solution?

 

[Bosshog]

With your incredibly simple and as-yet overlooked idea in mind (and I'm thinking to myself "why didn't I think of that") I decided to look for the sensor values for the O2 sensors.

Houston, we have a problem.

The ECM doesn't just monitor the return values. If it did, we'd be just fine - 0V means a lean running motor, 1V means a rich-running motor (yes, that's ONE VOLT, not 12V with an idiot typist missing the '2').

Unfortunately for us, the sensor's response rate to changes is monitored. The ECM will send a pulse to the sensor and the sensor has to respond within a given time, or it is considered faulty and the ECM decides to throw a fault and go back to default mode. Shit, shit and shit.

I think we can probably discount this test, since the ECM is so adamant that the sensor not only has to be there, it has to respond within a given time frame, so a resistor just won't do the job either - sorry about that Gus, the experiment is off!

I wonder if ChipIt could advise whether they have - or could have - a solution?

If this wasn't a public forum I'd be swearing about now - but thankfully Tony has done that for me!

That now means that Robert from Chip It needs to remap the ECU for us... please. Such as these guys in the UK are doing (DPF Removal / Delete | ECU Remapping | Chip Tuning | Diesel Tuning | ECU | ECU Remap).

Grrr...

 

[Old.Tony]

There is ONE ray of sunshine in all this: we've learned a bloody lot.

I think for the chip to do its work properly it's going to need to know the current crank angle so it is aware of which cylinder SHOULD be on its compression stroke and which one is on its exhaust stroke in order to remove the latter injector commands.

I don't know how deeply the chips actually go - the guy at the caravan & camping show in Sydney from DP said it was just intercepting the injector signal and extending that. If that's the case, and an injector is being opened during an exhaust stroke, we're only making our consumption problem worse by using a chip.

As for that site: we're not only trying to handle the DPF regen exhaust-stroke injector pulses, but there are exhaust-stroke injector pulses aimed at the CAT.

The O2 sensor is used by the ECM to monitor the fuel mixture, both for the CAT and for how the vehicle is performing at the time. I am not sure these guys have paid a lot of attention to the O2 sensor and the stuff we've discovered about the CAT and its NOx removal (which is what the O2 sensor/CAT/ECM interaction is all about).

My guess on how it actually works in practice is like this:

O2 sensor monitors the oxy level in the exhaust stream to determine the richness of the fuel mixture in real time. The ECM adjusts the injector duration based on this, engine load, engine temperature, throttle position, vehicle speed etc (including "air con compressor active" and more).

However, the ECM also does two types of injector pulses during the EXHAUST stroke...

1) a long one for DPF regeneration when the engine is operating at normal termperature and is turning over at or above 1600rpm.

2) a short one for CAT operations, the diesel is a reductant hydrocarbon for the purpose of catalysing the NOx molecules into N2 and O2, H20 S2 etc.

We want BOTH of these removed, really. The ideal way is for any injection-controlling chip to simply ignore exhaust-stroke injector commands and hope that doesn't trigger an alarm in the ECM.

Sounds about right?

 

[Bosshog]

OK I have the bit between my teeth now!

I spoke at length today with Justin from Chip It today to see if he'd be prepared to remap my ECU. I actually didn't get a answer on that - as we got side tracked... (note to self... call Justin back).

Anyway a DPF delete and an aftermarket dump/cat can be done without the white smoke.

The trick is to pull the three-wire pressure sensor connector adjacent the ABS control on the inside passenger side panel of the engine bay.

By doing so disables the ECU's ability to monitor the state of the DPF without also putting the vehicle into limp mode. It does throw the check engine warning light

So as you can see I did this today and I can confirm that the vehicle runs pefectly (Quite by chance 35K was on the odo).

You need to remember to plug it back in and reset the ECU before a service to remove the fault code.

As too a longer term fix (i.e. one that does not throw the warning light) both Justin and burgo (from the forum and whom I have had spoken to several months ago as he is an engineer who has attempted to have Nissan conduct a recall over the DPF) believe that the O2 sensor needs to be tricked into giving the right reading by modifying the environment it sits in. Burgo has experimented with alfoil wrapped around the end of his O2 sensor probe with "85% success". The 15% failure was when the alfoil falls off. Justin says it may be as simple as moving the probe further out of the gas flow so that it doesn't get an accurate reading. Justin is experimenting with this on a D40 next week.

So I am putting the ute on a hoist on Friday morning and I am going to experiment with moving the probe further out of the delete pipe.

The race on and lets hope one of us solves this.

Bosshog

 

[Chip Tuning]

Thanks or that Bosshog. Saved me a write up