VW TDI forum, Audi, Porsche, and Chevy Cruze Diesel forum banner

1 - 20 of 113 Posts

·
Premium Member
Joined
·
23,902 Posts
100% yes it'll throw error codes. I don't even think it would run well without it since the computer might send the car into limp mode if it doesn't get expected feedback from the various sensors. You have to have an engine tuner delete it in the software. Part of it is that the exhaust self clean cycle will be dumping fuel into the exhaust without the DPF in place. Here is more on the system: http://www.myturbodiesel.com/1000q/DPF-Adblue-FAQ-VW-Audi.htm

FYI, the car's emissions will go way up and if you have state visual or smoke inspection you'll definitely fail.

EDIT: Yes it will run, I was told that the car would go into limp mode but it appears not.
 

·
Registered
Joined
·
53 Posts
100% yes it'll throw error codes. I don't even think it would run well without it since the computer might send the car into limp mode if it doesn't get expected feedback from the various sensors. You have to have an engine tuner delete it in the software. Part of it is that the exhaust self clean cycle will be dumping fuel into the exhaust without the DPF in place. Here is more on the system: http://www.myturbodiesel.com/1000q/DPF-Adblue-FAQ-VW-Audi.htm

FYI, the car's emissions will go way up and if you have state visual or smoke inspection you'll definitely fail.
Why will emissions go way up? It's burning the same amount of soot (just all the time, instead of infrequent bursts), and with a proper tune the fuel injectors wont be squirting fuel into the exhaust to burn off the soot. I'd say overall emissions will go down and DPF is just to make it so you don't see dirty black soot out of the exhaust.
 

·
Registered
Joined
·
23 Posts
Discussion Starter #4
100% yes it'll throw error codes. I don't even think it would run well without it since the computer might send the car into limp mode if it doesn't get expected feedback from the various sensors. You have to have an engine tuner delete it in the software. Part of it is that the exhaust self clean cycle will be dumping fuel into the exhaust without the DPF in place. Here is more on the system: http://www.myturbodiesel.com/1000q/DPF-Adblue-FAQ-VW-Audi.htm

FYI, the car's emissions will go way up and if you have state visual or smoke inspection you'll definitely fail.
You mentioned having the engine tuner remove the software for it. So after you do this can you remove the DPF? Also the whole reason I'm inquiring about this topic is because I plan on an ECU re-flash for the 140-170hp increase. A lot of the manufactures recommend a DPF delete. Is this a physical delete or software one?
 

·
Premium Member
Joined
·
23,902 Posts
Why will emissions go way up? It's burning the same amount of soot (just all the time, instead of infrequent bursts), and with a proper tune the fuel injectors wont be squirting fuel into the exhaust to burn off the soot. I'd say overall emissions will go down and DPF is just to make it so you don't see dirty black soot out of the exhaust.
Because the DPF reduces particulate emissions, it doesn't just capture and burn them off in spurts. If VW could have passed emissions without fitting an expensive DPF they would have done so.

Is this a physical delete or software one?
Both physical and software. I don't know how the engine would run if you just cut the DPF out but I know it won't run right without the software accounting for it.
 

·
Registered
Joined
·
82 Posts
Why will emissions go way up? It's burning the same amount of soot (just all the time, instead of infrequent bursts), and with a proper tune the fuel injectors wont be squirting fuel into the exhaust to burn off the soot. I'd say overall emissions will go down and DPF is just to make it so you don't see dirty black soot out of the exhaust.
To clarify what Chitty responded with, the DPF stores soot permanently. It doesn't store it for a little while and then empty itself during a regen cycle.

Soot is the result of incomplete fuel burn, which is an inherent part of burning diesel fuel: it burns slowly, which is a challenge for piston diesel engines since they require rapid, frequent combustion events to produce power.

The DPF stores soot, and the regen cycle adds heat (by way extra fuel into the DPF) t to "complete" the burn, which turns the stored soot into stored ash. The DPF has a finite life: when it's full of ash, it needs to be replaced. Little or no soot stored in the DPF is ever emitted.

Removing the DPF will result in a huge increase in emissions, and the worst kind too, since soot is much more immediately harmful than greenhouse gasses. Also, unless you also remove the catalytic converters downstream of the DPF, I suspect that they would become clogged with soot rather quickly.
 

·
Premium Member
Joined
·
23,902 Posts
Hmm thats something to think of since I'm sure an ECU re-flash will mean even more soot.
Just to clarify something, the DPF is a filter. The other things are catalysts. The construction of each passageway on the DPF is a dead end, meaning that it really is a filter. The construction of each passageway on the other catalysts are tubes. Some stuff can pass through them but too much can clog them as well. They were surely designed to work with the DPF so I don't know how much it would take to clog them.
 

·
Premium Member
Joined
·
23,902 Posts
Anyone have an estimated life-span for a DPF?
The end of life for the DPF is until it can no longer be cleaned, which is pretty much until the stainless steel hosing rusts out.

It must be removed and cleaned when soot loading reaches 45 grams. VW says to check it at 120,000 miles and every 10,000 miles afterwards. Take a look at the immobilizer page, on page 2 it shows how to check.
 

·
Registered
Joined
·
53 Posts
So, just a little clarification here as to what the DPF actually does during the regeneration.

During passive regeneration the soot particles are continuously burned without the intervention of
Engine Control Module (ECM) J623.

This occurs primarily at higher engine load, such as in highway driving, when exhaust gas temperatures
range from 662°F to 932°F (350°C to 500°C).

At these temperatures the soot particles are converted into carbon dioxide through a combustion
reaction with nitrogen dioxide.

(Self Study Program 826803 2.0 Liter TDI Common Rail BIN5 ULEV Engine)


So particulates are converted in CO2 not ash, and are then utilized further downstream in follow-on exhaust treatment and are utilized in the NOx catalytic converter.
 

·
Registered
Joined
·
82 Posts
This occurs primarily at higher engine load, such as in highway driving, when exhaust gas temperatures
range from 662°F to 932°F (350°C to 500°C).

So particulates are converted in CO2 not ash, and are then utilized further downstream in follow-on exhaust treatment and are utilized in the NOx catalytic converter.
2 Things that confuse me about your explanation:

1. Highway cruising is a very low engine-load situation.

2. "Ash loading" seems to be a legitimate issue that defines the life cycle of a DPF until you clean it. Perhaps CO2 is a byproduct of DPF regen, as soot is burned more completely during DPF regen. But if regen doesn't result in ash, wouldn't the DPF never need cleaning?

Or are you specifically talking about passive regen, in which high-load operation inherently reduces the amount of soot produced because of more complete combustion?
 

·
Premium Member
Joined
·
23,902 Posts
1. Yes, highway drving only needs around 30 hp but as soon as you accelerate or go up a hill, the load goes way up, higher than what you'd see in steady driving at a much slower speed. Drag also adds load since the increase in drag is the square of the increase in speed.

2. The DPF needs cleaning because there is stuff that doesn't get burned like metals from engine wear that are in the engine oil and the additives in the oil. VW's 507.00 oil is very low ash which helps extend the life of the DPF, I don't know how the additive packs are different from other low ash oils though.

I will clarify these points in the section 507.00 engine oil required for VW TDI and Audi TDI with DPF filters in the FAQ article.


Also, to answer some earlier posts, I talked to a tuner and they verified that the engine will go into limp mode if you remove the DPF without the appropriate engine tuning.
 

·
Registered
Joined
·
53 Posts
Thanks for that explanation chittychitty, it was very complete.

Speedracer, passive regen is the only time the manual states specifically the chemical output of the regen process. It does however state that active regens occur at a much higher temp, somewhere around 1300F.
 

·
Registered
Joined
·
1 Posts
Who has actually done this successfully? Is it something that can be removed and then put back on with a replacement pipe? Will a car without DPF damage the cat? Will a car without DPF fail the sniffer or visual or both?
 

·
Premium Member
Joined
·
23,902 Posts
The DPF cannot be removed without an engine retune. I have since talked with people who have done this and the car instantly goes into limp mode without the DPF due to the various sensors that the ECU is monitoring. The DPF and CAT are in the same physical unit and it will fail emissions tests due to the check engine light that you have without a retune.

Also, it's easy to see if a 2009+ has had the DPF removed - the tailpipe has soot. If you look at the tailpipes in even high mileage 2009+ TDI, they are sparkling clean. That is how effective the DPF and other emissions stuff is. I doubt emissions testers will fail someone off that though.
 

·
Registered
Joined
·
2 Posts
VW worked long and hard to develop a clean burn diesel technology to meet US EPA regulations. I for one was happy to see the reintroduction of the VW diesel in the US (2009). The particulate filter prevents the release of materials which are extremely harmful to the human lung. The particulates are not visible under normal driving conditions so one might ask, what's the harm in removing my emissions equipment? Well for those of us that have been around for awhile, the term "blow the soot out of it" is a great illustration. You may have noticed this phenomena when someone in front of you accelerates at a rapid pace, say on a freeway on ramp.

If you are lucky and live long enough, one day you will realize, fast is never fast enough. Think about it.
 

·
Registered
Joined
·
29 Posts
Thread bookmarked for it's sheer awesomeness and completeness - great work, ccbb!


Not that I'd ever WANT to delete the DPF
a. 140hp is plenty for me
b. I abhor excessive emissions - if not for the relatively clean burn of the TDI as sold, I would own something else
... but I have a couple of addon questions ...

1. How does VW manage the 170HP variant of this engine? Do they use a Urea tank tor educe emissions, like they are in the new Passat TDI?
2. How self-doable is the DPF clean? Is there a write-up? I couldn't find one in a cursory search, but based on the notes above, it sounds like the manual describes it adequately!
 

·
Premium Member
Joined
·
23,902 Posts
The 170 hp variant isn't sold in the US :) It has different fuel injectors, turbo, and a few other items. The 170 jetta tdi cup race cars that were used in the US were off road only. They never went on public roads so no emissions.

I don't know if it's possible to self clean the DPF as in "it's totally clogged so it's off the car". If it were that easy, truckers would just blow it out with compressed air. I know they have special machines to clean truck DPF but it could just be to catch all those nasty particles that I wouldn't want to breathe in or have near me.
 

·
Super Moderator
Joined
·
9,546 Posts
A friend of mine markyboy76 had his Seat Leon chip tuned. He removed the DPF and put a replacement pipe in its place. He went back to the tuner and they re-did the ecu to ignore/disable the DPF so no faults show up.
 
1 - 20 of 113 Posts
Top