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DPF Removal Dilema - Gutting the DPF vs phyiscal removal?

Discussion in 'A3/S3/Sportback (8P Chassis)' started by theo289, Apr 26, 2013.

  1. theo289
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    theo289 Member

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    [Apr 26, 2013]
    Hi All,

    I am aware there are literally hundreds of posts on here about DPF removals on A3's and remaps but i haven't yet seen one about getting the physical DPF removed vs getting the contents of it gutted - one dilema which i am currently presented with.

    Having my DPF light come on as frequently as 4-times a month, its now become more of an annoyance more than anything and want some advise from you guys!

    There is obviously this crappy legislation coming in about the DPF filter but everyone i speak to, they are unsure of what to do, what to recommend and how to say it which makes me slightly more worried about getting the DPF removal (because the last thing i want to do is buy a DPF if i get one removed when i originally got it removed as it was a massive ball ache!).

    So here is the dilema....some people say 'we will take the whole DPF filter out' others say 'we will leave it in, cut around the welding and then put it all back on'.

    Any advise is greatly appriciated!
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  3. Brodster
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    Brodster Shark Performance In Scotland Regional Rep Site Sponsor VCDS Map User

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    [Apr 26, 2013]
    Currently there is NO new legislation being introduced reference the DPF. And the decision is up to you. I currently do DPF removals and out of the 10 or so I have done up to now it has been the customers decision to keep the cannister and remove all the gubbings. This way it looks totally standard when everything is put back together. There is no biggie of fitting a by-pass pipe either. Its actually easier fitting a new pipe rather than cut and weld. If there is going to be new legislation brought out with the DPF in mind then Joe Public will know well in advance and will have time to rectify IF there is at all going to be changes made...... I havent heard anything to date that will alter what I relate to my customers so I hope this helps.
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  4. miw615
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    miw615 Member

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    [Apr 26, 2013]
    Be careful when it comes to an MOT - I have asked similar questions and there seems no clear position regarding having an MOT carried out when a DPF has been removed - however I noted this on the AA website................

    "The exhaust emissions standards for new cars have effectively required fitment of a DPF in the exhaust of diesel cars since 2009 when the 'Euro 5' standard came into force. In fact, many cars registered before 2009 will have had one fitted too in anticipation of the change in standards."

    With this in mind I would be cautious in changing the original system - in a couple of years time you could well have to put it all back to original spec!
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  5. theo289
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    theo289 Member

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    [Apr 26, 2013]
    Is your A3 < 2008? If so do you have a DPF and had it removed?

    Cheers!
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  6. miw615
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    miw615 Member

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    [Apr 26, 2013]
    Yes I have an A3 - 2010, no I have not had the DPF removed, but my main worry is that because of my low mileage (about 8000 miles a year) I could well have problems in the future and like you am not too sure the best plan of attack.
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  7. Brodster
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    [Apr 26, 2013]
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  8. miw615
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    miw615 Member

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    [Apr 26, 2013]
    What's interesting is that the same subject comes up in many other forums especially Merc, Jaguar and Peugot all discussing the same issues :unsure:
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  9. miw615
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    miw615 Member

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    [Apr 26, 2013]
    Interesting reading - am I right in saying that legistation could change "when-ever" and what about the issue of "type-approval" ?
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  10. harvz
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    harvz Member

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    [Apr 26, 2013]
    If u just gut it and leave the casing is this not giving the same Performance as a straight pipe?

    If the performance will be the same why not just opt to gut it to be safe? Dpf removal won't really effect emissions. Why would u put a straight pipe in? Unless you think there would be a performance gain
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  11. davesimmo
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    davesimmo Member

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    [Apr 29, 2013]
    This is what is stopping me from doing mine. However, on reading this, it looks like I would be ok as my car was registered Dec 2008. correct me if I am wrong please... Could be bye bye DPF after all...... :hubbahubba:
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  12. MrLapou
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    MrLapou Well-Known Member

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    [Apr 29, 2013]
    Could total removal and fitting a by-pass pipe be classed by insurance companies as a modification?
    It'd be easier to spot compared to a jutted DPF box.
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  13. Brodster
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    [Apr 29, 2013]
    This is why the internals are removed and the original cannister kept.......JUST INCASE there is a change to the regs. The boy in my workshop who has been in the industry for many years says you always get a heads up of MOT reg changes and it can take years for them to be adjusted and implemented so its not like going to be an overnight change or even in afew months.
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  14. Brodster
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    [Apr 29, 2013]
    I will take a picture of a DPF cannister thats had the internals removed and its been welded back up and you wouldn't have a clue its been done. Some DPF's are very difficult to see whilst fitted to the vehicle so to anyone having a glance inside the engine bay everything seems spot on.
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  15. Lee540
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    Lee540 Member

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    [Apr 30, 2013]
    I thought that common rail engines were designed to work with the DPF, whereas PD engines weren't and hence issues with pre-09 cars? I mainly do short journeys but lots of them with the weekly blast down the dual carriageway. No DPF issues here after 9k so far.
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  16. theo289
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    theo289 Member

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    [Apr 30, 2013]
    The issue was with the PD engines (unfortunately like mine).

    I have now booked in for the DPF delete and Remap but opted for the gutting just as a safe guard if in the event anything does become apparent. From speaking to the garage i'm going to, the chaps there said that if in the event that anything were to happen, as they did the DPF delete, they would take the car back for any necessary work (i.e to pass it on an MOT :sm4: )

    What the garage i'm going to do is cut around the welding of the current DPF and then re-weld it back on to ensure visually together.

    Will provide a review once i have the 170 BHP > 200 BHP and the torque!

    Wish you all good luck with your DPF deletes!
    #15
  17. Rick @ Unicorn Motor Dev.
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    Rick @ Unicorn Motor Dev. Site Sponsor Site Sponsor

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    [Apr 30, 2013]
    There is no performance difference between a pipe and gutted canister.

    Rick
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  18. max69vk
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    max69vk Active Member

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    [Apr 30, 2013]
    Dont mess with the original welding as that will stand out like a sore thumb! Cut a plate out of the DPF on the side that goes against the engine block, gut & weld back in place. Once its re-fitted there's no way of telling its been done (other than tapping the canister & listening for the hollow sound). Below are some pics of a DPF we 'semi gutted' on a friends PD170, usually most people would totally gut the canister but this was done as an experiment to see if we could still make the DPF sound solid if tapped & still provide plenty of flow. There's no need to wory about the honeycomb block breaking up as its rock solid & withstood a good blast with a professinal jet washer without deteriorating or breaking up in any way at all. Rather than beat the innards out with a hammer we used an angle grinder with a 1mm metal cutting wheel & then tapped out what we'd cut...

    Starting to cut
    [​IMG]

    Metal plate removed
    [​IMG]

    Cutting into the honeycomb
    [​IMG]

    Close-up of DPF honeycomb cross section (FYI)
    [​IMG]

    50% depth of honeycomb centre section only removed
    [​IMG]

    Edges of remaining honeycomb bevelled to help flow (I dont think this was really required as enough material was already removed)
    [​IMG]

    Plate in position ready for re-welding
    [​IMG]


    I never took a picture of the unit it back in situ (as I didn't fit it) but you cant see that the DPF has been tampered with, & if tapped or knocked it still sounds like the unit is internally intact rather than a hollow box. 5000 miles or so later on the car there's been no problems with it at all so when I get round to doing mine I'll be doing it the same way :)
    #17
  19. Tempy
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    Tempy Member

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    [Apr 30, 2013]
    Mechanically is that all it is? Gutting the honeycomb centre?

    If that's the case then for arguments sake if you were to gut and replace and then new testing were to come in, will you be able to simply re-open and re-fit the honeycombed centre? or would it require a whole new DPF?

    I've heard replacing the DPF can be around £1,500 if it goes tits up. That is quite a large bill to be facing down the line should the test suddenly change. That's what puts me off gutting and remapping. Especially as I have a CR engine and have not really had any DPF issues except when I first got the car and didn't realise how to drive to prevent the need to regen.
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  20. max69vk
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    max69vk Active Member

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    [Apr 30, 2013]
    Yep thats it, nothing mechanical, just a PITA to get off & refit. If you gut the DPF there is no way back, the one we used was already fubar so thats why we attacked it. Personally I wouldn't bother gutting a DPF on a CR TDI as they have an additional catalyst (which the PD didn't have) to help keep the temps high enough to burn the soot out + its a cleaner burning engine anyway so the soot levels are lower to start with.
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  21. theo289
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    theo289 Member

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    [Apr 30, 2013]

    Those images are nuts! Definitely going to ask the guy gutting mine if he can provide some before and after images of the DPF filter. How do you find the drive now? - is it a lot smoother, faster, better?

    Did the above images come out of your car?
    #20
  22. max69vk
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    max69vk Active Member

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    [Apr 30, 2013]
    It was done on a friends car but I've driven it, he's only on a stage 0 remap (DPF remove only) whereas I'm on a Stage 1 with the DPF still intact & his is definately a massive improvement on the standard engine So much smoother power delivery, better responsivness, no smoke, & no pesky regens!
    #21
  23. dex140
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    dex140 Member

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    [Apr 30, 2013]
    Are they still pusing out 170 at stage 0? I was considering going there first then stage 1 at a later date
    #22
  24. max69vk
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    max69vk Active Member

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    [Apr 30, 2013]
    With a DPF in place & standard map I was reading 192 on an accurate RR. Set your car up properly and they far out perform the quoted output. Stage 1 you should be easily looking around 210+
    #23
  25. theo289
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    theo289 Member

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    [Apr 30, 2013]
    Thats crazy stats! Have you upgraded your air filter?
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  26. Brodster
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    [Apr 30, 2013]
    Would run even better with EGR delete software uploaded too.
    #25
  27. max69vk
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    max69vk Active Member

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    [Apr 30, 2013]
    No upgrades, just a very clean & well set up top end, using super diesel too. I was going to do an EGR delete but it does serve a purpose beyond the environmental pap that gets thrust down our throats, so I've now used a reducing gasket rather that a total delete. The RR was done with the car in totally standard form & everyone was quite surprised, especially the guys from AMD who were having a mass Subaru testing session down there at the same time...
    ImageUploadedByTapatalk1367344280.808973.jpg
    Forgot to mention the turbo was changed about 50 miles after this RR as it was found to be knackered!
    #26

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