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Silly question on Minicats...

Discussion in 'Technical Q&A' started by Wayne 962, Nov 14, 2019.

  1. Wayne 962

    Wayne 962 Formula Junior

    Nov 27, 2003
    434
    Hi all. 2000 Ferrari 360. Fabspeed headers. I bought a set of Fabspeed minicats to run on the car since we replaced the stock setup with precats with the headers. There are no instructions included with any of the Fabspeed products. I placed the minicats in front of the front two O2 sensors, simply assuming that since there was a missing cat there, the cat should be placed in front of the sensors.

    We're getting some immediate Check Engine Lamp (CEL) codes after about 10-15 minutes of the car running. These are both on the left and right side:

    P1198 - Rear Oxygen Sensor (Sensor 1): Throttle Lo (LEFT)
    P1135 - Rear Oxygen Sensor (Sensor 1): Throttle Lo (RIGHT)

    When I got these errors last week, I decided to start fresh and I simply replaced all four O2 sensors with fresh ones. The car also has new MAF sensors, new spark plugs, and all new coils, which were replaced a few months ago.

    I'm assuming it's caused by these minicats perhaps being placed in the wrong spot or something, but I figured I would ask the board here first for advice?

    Thanks!

    -Wayne
     
  2. JoeTSI

    JoeTSI Formula Junior
    Silver Subscribed

    Dec 16, 2015
    875
    Huntsville, AL
    Full Name:
    Joe K.
    Wayne,

    You have them reversed, they should be downstream since the downstream O2 measures the efficiency of the catalytic converter.
     
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  3. Doctor Mark

    Doctor Mark Formula Junior

    Dec 15, 2005
    485
    Georgia
    Full Name:
    Mark Gronsbell
    Have you considered contacting Fabspeed and asking for installation guidelines?
     
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  4. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    16,714
    USA
    Full Name:
    Hugh G. Rection
    What Joe says, the mini cats would be installed in the post catalyst position or "rear sensor" on each side. That is where they always go
     
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  5. Tarek307

    Tarek307 Formula Junior

    Sep 26, 2018
    355
    Long Beach, CA & Alexandria,Egypt.
    Full Name:
    Tarek Salah
    hopefully the OP cares to participate and update us, i'm having fabspeed headers & evoflow cats installed and i'm anticipating that i'll probably get CEL as luck isn't usually on my side lol so would like to hear more about solutions
     
  6. JoeTSI

    JoeTSI Formula Junior
    Silver Subscribed

    Dec 16, 2015
    875
    Huntsville, AL
    Full Name:
    Joe K.
    Tarek,
    Are you purchasing mini-cats? I had the Big Daddy mini-cats on my Fabspeed header/Topspeed high flow 200 cell cats and NEVER had a CEL. You will most likely get one if you are relying upon the high flow cats only though. Keep us updated!
     
  7. Tarek307

    Tarek307 Formula Junior

    Sep 26, 2018
    355
    Long Beach, CA & Alexandria,Egypt.
    Full Name:
    Tarek Salah
    i don't even know where to start or what mini cats are, i've heard about those and about 02 extenders .
     
  8. JoeTSI

    JoeTSI Formula Junior
    Silver Subscribed

    Dec 16, 2015
    875
    Huntsville, AL
    Full Name:
    Joe K.
  9. Tarek307

    Tarek307 Formula Junior

    Sep 26, 2018
    355
    Long Beach, CA & Alexandria,Egypt.
    Full Name:
    Tarek Salah
    Joes how many of those should i buy? and which one exactly? i see they have a few diff ones. Do these go on instead of the 02 extenders? My shop told me not to order extenders and that they break or come loose and they always have to end up removing them and to wait and see if i even get CEL after installing the headers/cats (i'm sure i'll get CEL)
     
  10. JoeTSI

    JoeTSI Formula Junior
    Silver Subscribed

    Dec 16, 2015
    875
    Huntsville, AL
    Full Name:
    Joe K.
    I bought two of the 90 degree angled O2 extender mini-cats, and they go after the catalytic converter to measure downstream cat efficiency. I never had a CEL thrown, even on a cold rev with tons of fuel in cold start trim. Again, I never had a single issue with them and plenty of members use them who go the headers route on their F-cars.
     
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  11. 2NA

    2NA F1 World Champ
    Professional Ferrari Technician Owner Consultant

    Dec 29, 2006
    17,585
    Twin Cities
    Full Name:
    Tim Keseluk
    Fabspeed specifically states that they are to be installed on downstream sensors only.
    https://www.fabspeed.com/universal-90-degree-o2-spacers-with-catalytic-converters-pair/
     
  12. Reid

    Reid Karting

    May 18, 2018
    52
    Full Name:
    Reid Fox
    there are several variations available it is basically a small filter that goes between the exhaust pipe and the downstream O2 sensor, it fools the downstream sensor by putting something between it and the upstream sensor. On a 360 I found that a 90 degree fitting works good for limited space and then the mini cat with the O2 sensor.
     

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