Diesel Particle Filter break down

[Bosshog]

I don't think it has anything to do with the CAT i might but i have removed mine and it still uses the same amount o fuel as it did with the cat in, i think that the DPF model has a richer tune or map it runs to help condition the DPF, in saying that tho you do save fuel by removing the DPF just still don't get the same economy as the manual version because of the map or tune the ECU runs, If we can find a way to remap the ECU we will be laughing i have emailed a mob in the UK RS Tuning who seem to think they can do it I'm going to have a chat to chipit before i send my ECU over there just see if they think it is possible.

Spoke at length with Robert about this. They are not interested as it is just too hard. It is too hard because the ECU is hard wired and they need to know the source code.

 

[Leprechaun]

The problem with the CAT is that whether it's there or not, every so often the ECU squirts some diesel out in the exhaust stroke to feed it. That's the problem - the ECU is rather blind in this respect, so if you remove the CAT, you need to find a way to remove the squirt as well.

Is this fact??

 

[westy350]

That's strange Bosshog i was talking to Justin and he said that they where looking at some sort of diagnostics instrument that was very expensive from the UK and he seem to think that it might be able to do the job if they get one he wanted to get one and have a demo with it to see if its would be worth the $$$, I told him he can test it out on mine if he wanted.

 

[Old.Tony]

Is this fact??

Bosshog himself noticed this. He removed his CAT and every 100-300km gets clouds of white smoke (unburnt fuel). Put the CAT back in and the problem goes (because the CAT uses the fuel as a reductant).

 

[Old.Tony]

Does this happen with the manuals as well tony?

All of our cars - even the petrol ones - have a CAT. The CAT's job is to remove nitrogen oxides (NOX) from the exhaust (remove? no, reduce). The reason why they only put a DPF in the auto is probably because the auto was already going to use more fuel, who'd notice a bit more?

 

[Leprechaun]

I had a manual D40 no CAT and no excessive smoke what so ever.

Has to be only related to D40's Auto with DPF's.

 

[westy350]

Bosshog himself noticed this. He removed his CAT and every 100-300km gets clouds of white smoke (unburnt fuel). Put the CAT back in and the problem goes (because the CAT uses the fuel as a reductant).

Personally i don't think its to do with the cat, if you remove the cat the oxygen sensor detects that something has changed and the ECU adds more fuel to try and and correct the problem. But if the DPF is no longer in the system the extra fuel has no where to complete a burn and comes out your exhaust as white smoke (unburnt diesel) if you leave the cat in you have no problems with white smoke my guess is that the high flow cats do not do as good job as the standard one only because when i had a high flow cat in the white smoke would only happen when starting the car from cold if i got it up to operating temp shut it down waited 5 mins and started again i could drive all day with no white smoke which makes me think that the standard one gets hotter quicker and start to work sooner and doesn't upset the 02 sensor if you can trick the 02 sensor by spacing it out you don't have this problem if you can delete all the code to do with the DPF from the ECU the 02 sensor would be doing nothing and you would be free to change your cat.

 

[westy350]

I had a manual D40 no CAT and no excessive smoke what so ever.

Has to be only related to D40's Auto with DPF's.

the manuals don't have a 02 sensor in your exhaust system telling your ECU that the cat is no longer in the system so they don't have any problems.

 

[SimonD40]

The problem with the CAT is that whether it's there or not, every so often the ECU squirts some diesel out in the exhaust stroke to feed it. That's the problem - the ECU is rather blind in this respect, so if you remove the CAT, you need to find a way to remove the squirt as well.

Has anyone blanked the fuel supply line to the DPF delete pipe to stop the squirt?

 

[Old.Tony]

Unfortunately in our 4-cylinder diesels that isn't easy: the fuel is squirted into the combustion chamber while the cylinder is on its exhaust stroke, the piston is rising and the exhaust port is open, forcing the fuel out into the exhaust manifold.

It might be possible in the V6 diesels, as they're saying that these have a separate 7th injector in the exhaust manifold.

 

[Bosshog]

That's strange Bosshog i was talking to Justin and he said that they where looking at some sort of diagnostics instrument that was very expensive from the UK and he seem to think that it might be able to do the job if they get one he wanted to get one and have a demo with it to see if its would be worth the $$$, I told him he can test it out on mine if he wanted.

OK Westy lets tackle them again and see what the real story is.

 

[Chip Tuning]

Yep, we have a delay in a componant for the boards. Sorry about that.

Thanks for the reply. I will definitely get the delete pipe as well but Chip it will not have for the next 2 weeks as per an email I received.

 

[D40 AUTO]

chipit are you looking for a way to fix the auto problem

 

[merchant]

chipit are you looking for a way to fix the auto problem

What auto problem?

 

[D40 AUTO]

What auto problem?

its not the box its the fuel it users

 

[Rickstar]

I have 3' aftermarket cat and no DPF.I too had the white smoke until I fitted the o2 extension that Bosshog suggested.No more white smoke and getting 11 lt/100 k down from 12.5. Now how simple would it be to swap the auto ECU for a manual one.I wonder if that would work ?

 

[Chip Tuning]

PM me about it

chipit are you looking for a way to fix the auto problem

 

[Old.Tony]

Now how simple would it be to swap the auto ECU for a manual one.I wonder if that would work ?

At a guess, I'd say no.

The ECU informs the auto transmission of things like vehicle speed, engine RPM, throttle position. In return, the TCM informs the ECU about what gear it is in, what the auto box temperature is, how many revolutions per minute the output shaft is doing etc.

I'm not sure a manual's ECU is wired to send or receive that information, and I'm betting that without info from the ECU saying that the driver is pressing the 'go' pedal, the TCM will just sit quietly and wonder what's poking it with the PRND2L lever.

 

[D40 AUTO]

PM me about it

sorry i got it wrong i ment the D40 auto fuel usage problem

 

[bshevelling]

dpf filter

Merchant

I don't have any answers for you I am sorry. However, like you I do have an 09 (2008) D40 which I too purchased in Feb this year.

I have nothing nice to say about this damn DPF. When I installed the 3" exhaust the guys at D&T who fitted it just bagged it and suggested that apart from stealing some valuable horsepower the DPF has been known to cause numerous problems and start grass fires during summer!

Its illegal to remove I know, but once the warranty has ended I'd be tempted to remove it completely. Removal is difficult due to all the sensors but not impossible.

Regardless, like the rest of us, I am sorry to hear about your dramas with Nissan. Next time unbolt the bloody thing yourself (good luck with that) and throw some kero in it followed by a match! Would be cheaper than 300 odd dollars!

Bosshog

when you remove it (dpf) knock the guts out off it and put the empty dpf filter back on it wiil run as normal because all the sensors are still in place.

you can buy a dpf remove pipe that does the same thing. on e-bay.