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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 3
    Silver Subscribed

    Dec 16, 2015
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    Huntsville, AL
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    Joe K.
    Wayne,

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

    Doctor Mark Formula Junior

    Dec 15, 2005
    537
    Georgia
    Full Name:
    Mark Gronsbell
    Have you considered contacting Fabspeed and asking for installation guidelines?
     
    Rifledriver likes this.
  4. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    17,031
    USA
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    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
    443
    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 3
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    Dec 16, 2015
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    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
    443
    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 3
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    Dec 16, 2015
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  9. Tarek307

    Tarek307 Formula Junior

    Sep 26, 2018
    443
    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 3
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    Dec 16, 2015
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    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
    17,698
    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
    59
    Vancouver Canada
    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.
     
  13. ke0kie

    ke0kie Rookie

    Jul 26, 2007
    47
    Dallas Texas
    Full Name:
    Scott Jones
    I have the Fabspeed mini-cats on my 2000 360 with Fabspeed headers and Tubi muffler.

    The mini-cats keep coming loose, where the right-angle adapter screws into the big cat, same exact issue on both sides (after I uploaded video I noticed other side was in fact looks exactly like the one I show).

    I took the mini cats off today, and scored severely damaged copper washers, so I'm wondering if those should even be used, or fit directly/dry?

    I might get the advice of a local exhaust shop on this...and if need be source some new washers to fit these back on.

    And another thing, these mini-cats stick out quite a ways...and that is part of why they are coming loose. Normal engine operation and movement is causing the stuck out part to work its way lose under its on weight / cantilever effect.

    I emailed fab speed to ask if they make a bracket, to SECURE the mini-cat to the exhaust...which IMO seems to be logical and needed, to prevent the mini cat from unscrewing itself during engine operation...

    Do comment and let me know your thoughts folks, and I took a video of what I'm saying to help illustrate:



    Cheers,

    Scott
     
  14. f355spider

    f355spider F1 World Champ
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    May 29, 2001
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    Probably need to use some sort of lock washer
     
  15. ssgharkness020147

    Rossa Subscribed

    Jun 12, 2006
    150
    Midwest
    I would recommend checking these out, they should work will in your application:

    https://www.nord-lock.com/nord-lock/products/washers/


     
  16. Metastable

    Metastable Formula Junior

    May 4, 2018
    424
    Canada
    A bit of a pia.... but you could probably safety wire it.
     
  17. MJGinTX

    MJGinTX Karting

    Mar 30, 2019
    99
    Colleyville, TX
    Not sure if I’m seeing it correctly but shouldn’t the mini cats be installed at the rear - those look like they are installed on the front.
     
    f355spider likes this.
  18. Reid

    Reid Karting

    May 18, 2018
    59
    Vancouver Canada
    Full Name:
    Reid Fox
    You have your old CATs installed. Unless they are gutted you don't need mini CATs. Fabspeed makes short pipes that replace the old CATs but you can just gut the old CATs and use them as pipes if you want to. A stock system has pre-cats inside the manifolds and then regular CATs between the manifold and muffler. If you removed or gutted the main CATs you need mini CATs on the DOWNSTREAM sensors to fool the ECM into seeing a different reading between upstream and downstream O2 sensors. If you put headers on you eliminated the pre CAT's (those are the ones inside the manifold known to break down) the MAIN Cats are the ones you have your mini cats on, they should be gutted and just used as pipes or else you don't need mini cats. If you insist, you just need to remove the elbow, put it in a vise and score the threads with a chisel, not the beginning of the threads so you can still start it in the hole but count about 3 threads in from the starting point and score the remaining threads, just one line with a chisel, it wont turn on its own because the threads are scored.
     

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