don't forget they only make soot because of the EGR they pour in. hopefully when they get Nox filters they can get away from EGR/Cat/DPF's.
Exhaust mod with DPF
- Thread starter justdrinkbeer
- Start date
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Hey guys what do you think is the best option for exhaust with dpf. Change it from the dpf back to a 3" without muffler or just replace the existing muffler with a peice of pipe? what are the stock exhausts are they 2.5" madrel bent? thanks.
I got a 3 inch from DPF back with high flow muffler. No change in exhaust note, louder turbo whistle and importantly some more killerwasps under my right foot.
Hey mate,
What brand exhaust did you get? was it an off the shelf one or a custom made one?
ta
Nissan would look to anything to void a warranty. That said, you can't come to much harm replacing the exhaust post the DPF.
Custom made Stainless Steel from D&T (:: D&T Performance Exhaust Centre ::). No increase in note coz of the DPF but the turbo whistle is more obvious.
Hey guys, wondering if anyone has done any mods before the DPF, has anybody removed the CAT? or bashed the guts out of the DPF and put it back in? also looking into a dump pipe and high flow cat and leaving the DPF untill warranty was over, just wondering if there would be any power gains or any change in economy? What about those tiapan exhausts anyone have any experience with them? thanks for any info.
I can't comment on such a modification in the public domain!
Suffice to say that I am aware that some people have removed the cat and DPF completely with no issues whatsover. I understand that those people that have done so, did it with much caution and kept the orginal fittings and pipe work so that it could easily reinstalled back to factory settings in the unlikely event that the ECU threw up a warning light.
Most importantly, I am reliably informed that a key aspect is to replumb all sensors back where they used to be in the dump pipe and DPF with enough thread to allow the sensors to be moved in and out of the pipe so that they can be adjusted to stop the ECU from throwing warning lights (O2 sensors in particular I have been told). I understand that this not easy as Nissan have used 'unusual' thread sizes which are not that easy to locate - but possible.
Some people choose to accept a higher level of risk; the upside of higher risk is often a greater reward, where reward equals better fuel economy, 'zero' turbo lag and truck-like exhaust note
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The fine was something like 120 penalty points. At the moment, 1 penalty point is $110, so the fine is $13,200 - and that's per offense, maximum. You don't have to be fined the maximum amount.
I would imagine that they could nail you for two offenses if you removed the CAT and the DPF even if you did it at the same time, since they're both distinctly different.
What's the chances of being caught though?
1) In a motor vehicle accident, your vehicle may be impounded and inspected. I can't imagine that they'd even bother checking inside, so if you leave the original and don't modify its external appearance, nobody's gonna ever know.
2) In a roadworthiness inspection conducted by an anal-retentive who's nitpicking because they've barfed up their breakfast, they went limp before finishing in the shower, or the saucy piece before you wouldn't give him a second eyeful.
3) If a police officer hasn't booked anyone for pollution and there's still one on his quota for the month that he needs to do, he can give you a canary for that causing an inspection.
Yeah, not very likely, and sadly it's the first one that's the biggest worry.
I would imagine that they could nail you for two offenses if you removed the CAT and the DPF even if you did it at the same time, since they're both distinctly different.
What's the chances of being caught though?
1) In a motor vehicle accident, your vehicle may be impounded and inspected. I can't imagine that they'd even bother checking inside, so if you leave the original and don't modify its external appearance, nobody's gonna ever know.
2) In a roadworthiness inspection conducted by an anal-retentive who's nitpicking because they've barfed up their breakfast, they went limp before finishing in the shower, or the saucy piece before you wouldn't give him a second eyeful.
3) If a police officer hasn't booked anyone for pollution and there's still one on his quota for the month that he needs to do, he can give you a canary for that causing an inspection.
Yeah, not very likely, and sadly it's the first one that's the biggest worry.
Hey guys , I went up to CHIPIT and got my exhaust done 3" all the way no DPF did a good job did take them 2 days tho so you would expect a good job. did about 65km after removing the dpf and the d40 started to blow white smoke lots and lots of white smoke! went back to CHIPIT and they told me they had never seen this happen before and I have a warranty issue and go the Nissan and get it fixed, anyways a bolted to DPF back in myself and the smoke has gone? anyone got any ideas? or had this happen? it seems a bit like the d40 was still trying to burn off the dpf even tho it wasn't there!
JPMC
Member
Did they put the sensors back in correctly to the new pipe or have they damaged one of the sensors?
You probably can't see the smoke now because the DPF and Cat are removing it.
Although in saying that white smoke is usually water in the engine or an injector leaning out so you may have something completely different to the exhaust that's gone wrong.
Also other people I know that have removed cat and dpf have had a little bit of smoke for the first hundred or so km's but then it disappairs, also it's normally black smoke too.
If it was the ecu trying to do a burn off the smoke would be black too.
You probably can't see the smoke now because the DPF and Cat are removing it.
Although in saying that white smoke is usually water in the engine or an injector leaning out so you may have something completely different to the exhaust that's gone wrong.
Also other people I know that have removed cat and dpf have had a little bit of smoke for the first hundred or so km's but then it disappairs, also it's normally black smoke too.
If it was the ecu trying to do a burn off the smoke would be black too.
Pure unburnt fuel also turns the exhaust white. Sticking injectors are noticeable from the white emission from the exhaust. I think your initial guess of a DPF regen being attempted is likely - and that's probably because the sensors aren't in properly.
If the sensors detect a measurable difference in pressure between the two, the ECU will start a regen cycle when it is able to. You should be able to avoid this by making sure the two sensors are connected but reading the same pressure.
Surprising that ChipIt were unaware of this, they definitely know about the DPF and offer a solution with and without one. Maybe they haven't done many, and yours is the first to try a regen cycle just after installation?
If the sensors detect a measurable difference in pressure between the two, the ECU will start a regen cycle when it is able to. You should be able to avoid this by making sure the two sensors are connected but reading the same pressure.
Surprising that ChipIt were unaware of this, they definitely know about the DPF and offer a solution with and without one. Maybe they haven't done many, and yours is the first to try a regen cycle just after installation?
You can't increase the amount of gas coming out of the exhaust, you can only let it flow more freely. Higher flow after the turbo doesn't equate with higher flow rates through the turbo, as the turbo size isn't changing.
You shouldn't have any problems, and may reduce the post-turbo EGT by doing it. Others have installed 3" exhausts with good results.
You shouldn't have any problems, and may reduce the post-turbo EGT by doing it. Others have installed 3" exhausts with good results.
high flow after the turbo reduces the back pressure in the turbo. it means turbo will flow a bit more and increase turbo rpm a little bit.
fortunately the ecu compensates for the changes easy enough. some earlier vehicles with variable turbo's have problems with exhaust changes as the ecu is to dumb to compensate for it.
You Learn Something Everyday!!
Well as the saying goes, you learn something everyday and accordingly my learning today was it was a silly idea playing around with my exhaust, chip and dyno the day before the family was heading off to see Lake Eyre!
The story is I removed the DPF over two weeks ago and it made a huge difference. I improved the Nav's fuel economy by more than one litre / 100 kms!! Furthermore, I have not had any trouble with it whatsoever with regards the ECU.
So, we moved to stage two - the dump pipe. Put a 3" inch cat free dump pipe in this week. Again no issues whatsoever and drove the Nav a couple of 100 kms. Gee a 3" dump pipe makes a difference with low down torque and turbo lag and a great note too!
So, we moved to stage three - dyno tuning it with my chip fitted. Did about 5 or 6 runs and leaned out the chip, i.e max mid range and top end power for the least amount of fuel in. That was yesterday. Again did a 100 or so k's yesterday and again no issues.
So to this morning...
Loaded up the Nav with the family and everything you could imagine you might need for a week in the desert and off we headed. Got 10 kms down the road and completely smoked out an entire intersection: white smoke everywhere
So I have reset the ECU but no change. The ECU is wanting to continuously run a regen and therefore dumping diesel when once the Nav is up to running temp.
The good news is no harm done and I have kept everything so I can reinstall the factory pipework and DPF and at least we weren't at Marree when it happened.
BUT since I have gone this far and ruined a perfectly good school holiday trip with the kids, I thought I might remain the forum guinea pig in the interest of good D40 science and see if we can beat the ECU. If not, then get the ECU reprogrammed. I’ll make up the lost ‘browny points’ next school holidays.
So, finally any ideas would be helpful. Especially as the pressure sensors should not be measuring any pressure differential with the DPF removed? But I now suspect that the ECU uses more than one means to determine whether a regen is needed. I wonder if the cat removal has upset the dynamics inside the exhaust pipe?
Josh (Westy350) has tried the same thing and got the same issue but he did the dump pipe at the same time as the DPF delete so I am guessing the 3" dump pipe and no cat is causing the sensors to tell the ECU to do a regen.
Thoughts?
I'll keep you all informed regardless.
Gus
Well as the saying goes, you learn something everyday and accordingly my learning today was it was a silly idea playing around with my exhaust, chip and dyno the day before the family was heading off to see Lake Eyre!
The story is I removed the DPF over two weeks ago and it made a huge difference. I improved the Nav's fuel economy by more than one litre / 100 kms!! Furthermore, I have not had any trouble with it whatsoever with regards the ECU.
So, we moved to stage two - the dump pipe. Put a 3" inch cat free dump pipe in this week. Again no issues whatsoever and drove the Nav a couple of 100 kms. Gee a 3" dump pipe makes a difference with low down torque and turbo lag and a great note too!
So, we moved to stage three - dyno tuning it with my chip fitted. Did about 5 or 6 runs and leaned out the chip, i.e max mid range and top end power for the least amount of fuel in. That was yesterday. Again did a 100 or so k's yesterday and again no issues.
So to this morning...
Loaded up the Nav with the family and everything you could imagine you might need for a week in the desert and off we headed. Got 10 kms down the road and completely smoked out an entire intersection: white smoke everywhere
So I have reset the ECU but no change. The ECU is wanting to continuously run a regen and therefore dumping diesel when once the Nav is up to running temp.
The good news is no harm done and I have kept everything so I can reinstall the factory pipework and DPF and at least we weren't at Marree when it happened.
BUT since I have gone this far and ruined a perfectly good school holiday trip with the kids, I thought I might remain the forum guinea pig in the interest of good D40 science and see if we can beat the ECU. If not, then get the ECU reprogrammed. I’ll make up the lost ‘browny points’ next school holidays.
So, finally any ideas would be helpful. Especially as the pressure sensors should not be measuring any pressure differential with the DPF removed? But I now suspect that the ECU uses more than one means to determine whether a regen is needed. I wonder if the cat removal has upset the dynamics inside the exhaust pipe?
Josh (Westy350) has tried the same thing and got the same issue but he did the dump pipe at the same time as the DPF delete so I am guessing the 3" dump pipe and no cat is causing the sensors to tell the ECU to do a regen.
Thoughts?
I'll keep you all informed regardless.
Gus
