Anyone had a CEL with catted Downpipe (No tune/piggyback)??

Discussion in 'B58 6-Cyl Engine, Exhaust, Drivetrain, Bolt-Ons' started by MA617M, Oct 24, 2019.

  1. MA617M

    MA617M Well-Known Member

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    As subject

    Going to DIY a dump pipe with a 4" high flow cat

    Wondering if anyone has seen a CEL with aftermarket cats

    :)
     
  2. MKVSupraPro

    MKVSupraPro Member

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    I did have a CEL pop up with my HFC downpipe on the stock tune.
     
  3. Twisted Tuning

    Twisted Tuning Well-Known Member
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    you can get a CEL, most "catted" downpipes arent enough to keep the code away.
     
  4. OP
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    MA617M

    MA617M Well-Known Member

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    Thanks guys.
     
  5. Cae

    Cae Member

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    So what would be the best possible solution for it? Im concern to as i am planning to mod mine too..was looking to do cusco braces and strut first , then going for with either akrapovic slip on, but for that price my understanding is doing downpipe be better bang for bucks ya..
     
  6. Twisted Tuning

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    in terms of power output on stock turbo, DP is your best back for buck exhaust wise. the exhausts out right now are mainly there just to change sound a bit. Flash tune will fix the CEL for downpipes.
     
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    MA617M

    MA617M Well-Known Member

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    I might just remove the centre resonator to start with for the volume increase, and go full 4" when I am ready for a tune (and flex fuel)

    Are there any issues running E85?
     
  8. Twisted Tuning

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    There is no true "flex fuel" capability yet. Butnits being worked on. No real issues with E85 as long as the tune is good and its adjusted probably. Or you'll have issues starting the car.
     
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  9. Haros

    Haros Well-Known Member

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    The Supra has not been fully accessible since launch. The ECU/DME has not yet been fully unlocked: for example I can’t just throw larger injectors into it yet and have it work with a larger fuel rail.

    For the codes, you can flash the car directly to stop checking the 02 sensor all together, hence no code. But you can not yet adjust its sensitivity.
    The alternate is a piggy back, but that would just Be manually clearing when it comes up.

    This is why Steph Papadakis has made the interesting choices that he did with his new 1000hp Supra build. He clarified he would make adjustments as the ecu is cracked in an interview.
     
  10. Twisted Tuning

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    I have all the injector tables. Why can't you just throw larger injectors in the car with a larger fuel rail?

    Direct injection....that's why. There are no DI injector upgrades for 95% of DI equipped vehicles out there. But the injectors that come in the car flow enough for 700-800whp by themselves.

    I also have the O2 sensor tables. But it's easier and faster to do it the check way of disabling. Once I have time. I will explore adjusting the ranges for tripping.

    I'll keep my reservations to myself about the route Papidakis chose for his build. Considering he is one of many making claims about this BMW platform that they really know nothing about. But I will follow his build just like anyone else building this car.
     
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  11. a90moe

    a90moe Well-Known Member

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    Think the same with the stock resonator since mid pipes are only slightly larger with no resonator and are north of a thousand dollar

    So axleback or slip on with that..
     
  12. larrymz3

    larrymz3 Well-Known Member

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    Does a tune (i.e. MHD or BM3) actually code out the catless DP CEL differently than just unchecking the box that says "OEM/Catted downpipes"?
     
  13. Twisted Tuning

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    Unchecking that "oem/catted downpipe" box simply re-enables the logic check for the rear cat efficiency. Basically undoes what the tune had programmed to deal with the CAT cels.
     
  14. larrymz3

    larrymz3 Well-Known Member

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    So, with catless dp and OTS map, shouldn't this be unchecked?
     
  15. Twisted Tuning

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    yes
     

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