D40 with DPF and CAT Exhaust Issues

[auggie]

2009 D40 Auto with DPF and CAT Deleted

Hi Folks

I've been a member on patrol4x4 for a couple years and recently stalking around here so i thought its about time i get involved as i have 2 D40's at the moment.

Tried searching and have read most of the threads i could find on this subject but it was hard to get a straight answer (if theres one?)

Firstly I've got a 2009 D40 Auto with cat and dpf.

I've been running a DPF delete pipe for prbably a year now with no problems. I've recently removed the cat and now its blows buckets of smoke and stinks of diesel, which i understand is common with this model.

Basically what i want to know is if i bight the bullet and buy a full 3inch system for it with a 200 cell Highflow CAT will this stop the nasties currently pouring out the exhaust.

Ideally i'd like to stop the "regen, diesel injection on exhaust stroke" system but im not sure of anyone in Aus that can do it yet.

Cheers!

Auggie

 

[jjohn]

There are guys doing the mod successfully. Someone will chime in for you.
A search of most recent threads should give you the answer. It wasn't that long ago it was discussed. GL

 

[auggie]

JJohn

Thanks for the reply. I'll Try the search again. I know its a pain when newbies ask the same questions that have already been answer a gazillion times. Anyone else's advice greatly appreciated.

i've been doing some ringing around and trawling online and i think what the problem might be is we have removed the CAT mid "regen" the cars now stuck try to complete the "regen" and cant finnish. I've heard this can happen Any ideas?

Ta

 

[Old.Tony]

The regen usually starts because the sensors detect a pressure differential.

In the front of the DPF (before the filter matrix) is a pressure sensor and there's another after the matrix. If the voltage returned from these sensors is too different the ECM figures a burn is needed. The process is really that simple.

So the question is "what caused the sensor difference?" DPF delete pipes sometimes have the sensors facing the exhaust stream again and it's possible that ONE of the sensors has more soot on it than the other. Others point the sensors towards each other in a separate pipe - I'm not sure if that's going to cause the ECM to start playing tricks either, because it's a complete PITA with things like the HO2S - if you watch the fuel rail pressure closely over time at idle, you'll see the rail pressure 'module' by 3-400psi. The ECM is looking for a corresponding fluctuation in oxygen levels in the exhaust - guaranteeing that you can't just stuff THAT sensor in the garbage bin.

The other obvious thing that it could be is a sensor failure.

Are you willing to take a look inside the delete pipe and see if it's just soot?

 

[mgermasi]

Hi Tony
I just came back from a trip in Italy and there they told that every third car gets the ecu remap to delete the DPF section complete.
My question is how long before we get that technology in here?????

 

[Old.Tony]

I guess when the next person that goes to Italy brings it back with them!

We've actually been able to have our ECUs remapped by sending the original unit to a company in the UK but I have two problems with that: one, I'd be without my car while the ECU was removed, and two: Australia Post steals your packages! There's no way I'm ever sticking my package in Australia Post ever again. Bloody thing itches from time to time, it's bloody embarrassing.

Seriously - we'd have to have someone who could afford to bring in or make the equipment to do it, and be smart enough to NOT screw things up. I'd say that's a rare find.

 

[4BYFOR]

Tony, as for the pressure sensors I just plumbed them back into each other and never put them into the delete pipe at all.. It all works fine it hadn't done a regen for over 100k until a few months ago and it was a half burn.. After I took it for a 15min strap nice and hard it was gone..

 

[mgermasi]

Well well that's very interesting what you did 4BYFOR.
You are saying that you took a pipe and you installed the 2 sensors at each side of the pipe, correct?
Also what do you mean with "it was a half burn"?
If it is so it sounds like you find the best and simple solution for the problem.
Thanks
Max

 

[4BYFOR]

Well well that's very interesting what you did 4BYFOR.
You are saying that you took a pipe and you installed the 2 sensors at each side of the pipe, correct?
Also what do you mean with "it was a half burn"?
If it is so it sounds like you find the best and simple solution for the problem.
Thanks
Max

Well the pressure sensors run off 2 rubber hoses all I did was remove one hose and plumbed the other back into it. This is the best pic I could take because the loop is behind the dump pipe.. Yeh it's worked out fine. As for the half burn it only blew white smoke after a drive then come to the lights stop and smoke after about 10 seconds it goes away until you drive and stop again.. A full burn is constant white smoke at any rev range driving or not pretty much..

 

[auggie]

Made a few steps forward last night after work.

1. Refitted the stock DPF and per standard with all sensors as stock.
2. One reset on the engine the DPF or as i call it the "Fart light" was illuminated on the instrument cluster.
3. Took the car straight onto the freeway and sat on 100kph and after roughly 17mins the DPF was cleared.

Also interesting is this vehicle dose not have a functioning CAT.

I was dubious without a working cat whether i could get enough heat in the exhaust for a full burn but hey it still works!

I managed to stumble accross a document online from the Nissan Learning academy. I has good diagrams, informationa dn QandA about Nissan DPF systems. It explains what roles the sensors play in the system or more importantly how i might be able to trick them.

Next plan is to reinstall delete pipe and see how it goes with no cat and no Dpf again. I've got several experiments planned so stay tuned.

 

[auggie]

UPDATE:

In Late April after clearing the DPF fault i had i re installed the DPF delete pipe again. The cars has had the cat removed also. After experimenting abit i've also been trailing something else.

After reading some documentation on the subject I found that the temp sensors in the exhaust are vital to the sucess of the regen process. They issue the feedback to the ECU along with the differential pressure sensors on the DPF.

The temp sensors are just basic RTD devices. I've calibrated them in our lab at work using a dry block calibrator which gives me very acturate temperature control up to 650C. Armed with this information i have replaced the temp sensors all together with a resistor of a specific resistance. The computer now thinks the DPF exahust temp is 550-650 area all the time and i believe is not post injecting any more.

The car has been running this setup since late April and has covered about 2500 K of mostly city with about 900km of highway driving. On adverage its using about 1.5 - 2 Litre per 100km less and it's not blown the slightest puff of smoke.

I'll continue to run it like this for more long term testing.

Cheers

 

[JPMC]

Nice work.

Thanks for the update I think this info will be very interesting for the guy's that have removed there DPF's and CAT's and having issues with smoke.

 

[steve1961]

god iam glad i got a manual

 

[Old.Tony]

I'm stumped - there's not supposed to be a temp sensor in the exhaust, but the ESM doesn't cover every little thing. Now that I think hard about it though, there'll be mention of it in the electrical layout diagrams, so I'll go rooting around in those to see if I can find it.

Brilliant work, btw. No exhaust-stroke injections would definitely save fuel and I'd be able to get mine under 10LPHK - I'd be a happy chappy. Easy enough for me to do on the cheap: hollow out the DPF with a tungsten drill bit, bolt the sensors into their own pipe and add your resistor to the EGT sensor.

Not ready to do it just yet - my DPF is still working fine, but saving 1.5-2LPHK is very tempting, because @ 30,000km per year that's a saving of about 600 litres of diesel. That's a trip across Australia.

Okay, I might piss off and contemplate that one, shit it's tempting to get the ol' Ryobi fired up right this minute!

 

[jjohn]

Nike

 

[auggie]

Cheers for the ecouragement everyone. I'm pleased with the results so far but more long term testing is needed.

Yes Old.tony there's actaully 2 temp sensors on the DPF pipe. One pre filter and one post filter.

Also i think if your cars already using around 12Lph you might not see such a big drop as yours fuel comsuption isnt bad already so your cars not wasteing much fuel. If my theorys correct the worse your fuel economy is to begin with the larger gain you should see from stopping the post injection. The car im testing with Spend most of it's life doing short city runs so its probably having to post inject regularly to get the heat build up in the exhaust. Just a theory

 

[Old.Tony]

I know there are two pressure sensors to determine whether or not there's a pressure differential across the filter matrix but I didn't know about the temp sensors.

Looks like I'm going to go digging through the electrical diagrams in the ESM again.

 

[JPMC]

I know there are two pressure sensors to determine whether or not there's a pressure differential across the filter matrix but I didn't know about the temp sensors.

Looks like I'm going to go digging through the electrical diagrams in the ESM again.

There is the 2x pressure sensors, the 2x temp sensors and 1x O2 sensor in the DPF.

Your manual may not show it if like mine it's for the early euro 3 models that didn't have a DPF.

As auggie said you may not see much improvement in your ute.
When I removed the DPF from my old one I didn't see any improvement on the open road but around town it did make a difference (240,000km in three years so mine ran pretty clean because it was 90% open road running)(also I didn't remove the CAT as at the time to many people were having problems when removing both but with this solution I would have removed both). So I'm guessing because of the economy you already get your improvement maybe very minimal but then in saying that you may well see an improvement when your towing the van as the engine works harder so will be producing more soot plus breathing easier from not having the DPF and/or the CAT will make it tow better too.

 

[Old.Tony]

I'm keen to find out the ECU's PID for those temp sensors, in that case.

 

[auggie]

PM me your email old tony and i'll send u a copy of my literature.