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Decat pipe bring on management light?

Discussion in 'A4/S4 forum(B5 Chassis)' started by badpanel, Jan 9, 2010.

  1. badpanel
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    badpanel Member

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    [Jan 9, 2010]
    I have just ordered a decat pipe for my 1.8t and was wondering if fitting it will bring the the managment light on because of the pre and post cat lambda sensors reading the same.
    If so what can i do to sort it?
    #1
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  3. jamie226bhp
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    jamie226bhp Member

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    [Jan 9, 2010]
    have a look on ebay as they do a sleeve that the lamda screws into which goes into the post cat hole which keeps it enclosed from the exhaust gasses thus given the lamda a different reading to the pre cat one
    #2
  4. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Jan 9, 2010]
    does your B5 even have two lambdas?

    AEB/AJL certainly doesnt, so unless the later DBW cars have it...
    #3
  5. Broken Byzan
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    Broken Byzan Photographic Moderator Staff Member Moderator VCDS Map User

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    [Jan 9, 2010]
    As long as you only have the pre cat lambda then no light will come on.

    I had a turbo back stainless exhaust on my AEB with no problems at all

    Its the later wideband cars that have the pre/post sensors iirc
    #4
  6. macca
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    macca Member

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    [Jan 9, 2010]
    on my AEB 98 a4 the decat pipe didn't matter as only one probe, my r32 with 4 probes, yes expensive, would through a check engine light if decatted. but these can be coded out i believe by remapping.
    #5
  7. staggspeed
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    staggspeed staggspeed

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    [Jan 9, 2010]
    Badpanel,can you tell me where you purchased your decat from?I cannot find any listed on e-bay.If anybody on here as one for sale to fit an aeb a4 engine please pm me.
    #6
  8. badpanel
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    badpanel Member

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    [Jan 9, 2010]
    Mine does have two on it and is a AWT engine! pain in the arse was hoping to put it on and run it for a while before having a remap.
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  9. macca
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    macca Member

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    [Jan 9, 2010]
    Look for THS decat, usually on ebay, has two lambda holes bu also comes with lower one plugged.

    i would change gaskets for new audi ones though as the ones that came with mine didn't last long.
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  10. badpanel
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    badpanel Member

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    [Jan 9, 2010]
    Yeh mine is a ths one and i should get it next week. Dont seem to be any for sale on ebay at the moment.
    #9
  11. badpanel
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    badpanel Member

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    [Jan 10, 2010]
    Do you have one? Any clues what to search for?
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  12. jamie226bhp
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    jamie226bhp Member

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    [Jan 10, 2010]
    on ebay.com and search for vw audi test pipe fix or mod and this should find some
    #11
  13. jcb
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    jcb Active Member VCDS Map User

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    [Jan 10, 2010]
    spark plug spacer or search vwvortex for Wayne angle block $30 IIRC
    #12
  14. badpanel
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    badpanel Member

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    [Jan 12, 2010]
    Cheers for that mate! Ordered one from the states should be here soon.
    Do you have a twin lambda on your car? if so did this mod work ok for you?

    Cheers.
    #13
  15. jamie226bhp
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    jamie226bhp Member

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    [Jan 12, 2010]
    only single i think but i haven't fitted a decat yet but was just trying to work out what bits i might need in advance
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  16. badpanel
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    badpanel Member

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  17. badpanel
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    badpanel Member

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    [Jan 24, 2010]
    Right then my adapter arrived from the u.s and have fitted it along with the decat pipe and so far no light on and has made a bit of difference to spool up and has made the exhaust note slightly louder witch is cool as my stainless system was too quite before.
    I'm pleased with it!
    Has anyone fitted a generic chip from anyone off ebay??
    #16
  18. jamie226bhp
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    jamie226bhp Member

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    [Jan 24, 2010]
    anyone else make a decat as ths just seem to keep putting the price up £100 now
    #17
  19. Lee Goodall
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    Lee Goodall ..got my head together!

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    [Jan 25, 2010]
    Why don't you just take the guts out of the CAT?.. costs you nothing and produces the same results!

    AWT engine code?.. must be one of the last B5 turbos?
    #18
  20. jamie226bhp
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    jamie226bhp Member

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    [Jan 25, 2010]

    don't really want to ruin a good cat but i'll see if i can find a worn one, aren't the ths one's a bigger diameter though
    #19
  21. badpanel
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    badpanel Member

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    [Jan 25, 2010]
    Yeh i beleive it is one of the latest b5's, any one know what turbo is fitted to an AWT engine code.
    And is a chip off ebay worth getting??
    #20
  22. Lee Goodall
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    Lee Goodall ..got my head together!

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    [Jan 25, 2010]
    Unless you're increasing the diameter of the entire exhaust system to match then I can't see that you'll gain anything by just increasing the diameter of the CAT to be honest.
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  23. Lee Goodall
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    Lee Goodall ..got my head together!

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    [Jan 25, 2010]
    It's a K03-029 turbo mate.. same as APU. Bigger than the AEB and AJL K03-005 turbo.

    Not had any experience with the ebay chips but AFAIK people have used the generic ones with good results. I suppose it all depends on the supplier.. might be worth creating another thread to see who people suggest.
    Last edited: Jan 26, 2010
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  24. jamie226bhp
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    jamie226bhp Member

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    [Jan 26, 2010]
    gonna fit a 3" exhaust at a later date when funds allow, but as i'm changing the turbo i thought i'ds decat aswell while i'm in the same area
    #23
  25. Lee Goodall
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    Lee Goodall ..got my head together!

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    [Jan 26, 2010]
    I see.. in that case yeah do it.

    Remember you need a friendly MOT man or you'll be swapping for a CAT again for each MOT.
    #24
  26. jamie226bhp
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    jamie226bhp Member

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    [Jan 26, 2010]
    exactly what i'll be doing, just need to get some good prices on exhausts now
    #25

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