Disconnect cat ecu? | FerrariChat
Buy

Disconnect cat ecu?

Discussion in '348/355' started by F355Bob, Sep 2, 2013.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. F355Bob

    F355Bob Formula 3

    Nov 4, 2003
    2,002
    Madison, Wisconsin
    #1 F355Bob, Sep 2, 2013
    What would happen if you disconnect the plug running from the cat thermocouple to the cat ecu? Would it go into limp home mode? Would nothing happen?
     
  2. Dave rocks

    Dave rocks F1 World Champ
    BANNED

    Nov 23, 2012
    16,047
    Orchard Park, NY
    Full Name:
    Dave Lelonek
    #2 Dave rocks, Sep 2, 2013
    I assume the car would throw a CEL since it would thing the thermocouple was bad
     
  3. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    29,270
    socal
    #3 fatbillybob, Sep 2, 2013
    In your case nothing except your cats/car would be unprotected. once you get to the 5.2 motronic you have to fool it. Search an old thread I started on it. We got 1 easy and 1 elegant solutions to the problem of very poorly engineered oem SDECU's. Another 355'er also wrote 3rd SDECU bypass method with home built PC board and circuitry.
     
  4. bosshog8

    bosshog8 Formula Junior

    Mar 13, 2011
    448
    Pinelands NJ
    Full Name:
    Demetrius
    #4 bosshog8, Sep 2, 2013
    If you disconnected your Cat ECU (SDECU) from the main harness then fatbillybob would be correct but if you just disconnected your thermocouples from the Cat ECU your cars Slow Down Light system, hence the SDECU, would light up and the car would be in limp mode.
     
  5. ernie

    ernie Two Time F1 World Champ
    Lifetime Rossa Owner

    Nov 19, 2001
    22,620
    The Brickyard
    Full Name:
    The Bad Guy
    #5 ernie, Sep 2, 2013
    On a 348 the only thing that will happen is, the ecu will store a silent code ((4121) the silent meaning it will not illuminate the check engine light). The engine will runs just fine. I have the cat ecu's and the thermocouples complete removed from my car, and it has run fine that way for many YEARS. It may even be around 10 years running with the stupid cat ecus disconnected/removed. Again, this is for a 348.
     
  6. John Glen

    John Glen Formula Junior

    Dec 30, 2009
    494
    Victoria, B.C, Can.
    Full Name:
    John Glen Wesanko
    #6 John Glen, Sep 2, 2013
    I totally agree. I have a 1990 348 ts and the cat ecu's are expensive junk. Just disconnect the plugs and everything works great !
     

Share This Page