TFI W/ 02 sensor

Discussion in 'TFI Questions Answered By Dobeck' started by flhtcrp, Aug 23, 2010.

  1. flhtcrp

    flhtcrp New Member

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    Is there a TFI I can use that don"t elimiate the 02 sensors? 2009 FLHTC
     
  2. Hoople

    Hoople Account Removed

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    The o2 sensors is what makes the A/F ratio run lean. (14.3-14.7) You have to bypass them in order to run outside of that window.
     
  3. flhtcrp

    flhtcrp New Member

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    Yes but don't a TFI change fuel pulse to richen it up?
     
  4. Hoople

    Hoople Account Removed

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    Yes Exactly.

    But if you left the o2 sensors working, they would see that extra richness and would tell the ECM to lean out. There would be a big tug of war going on.

    You really need to disable them which will force the ecm to go by "look up tables" only,, and then "stack" some extra pulse width on top of the look up table value using the TFI.
     
  5. Hoople

    Hoople Account Removed

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    Did not see this was official Support area. Please delete my replies.
     
  6. DobeckTechSupport

    DobeckTechSupport Active Member Product Contributor

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    Great answers Hopple and you are absolutely correct.

    If you did not want to bypass the O2 sensors then you would just have to turn the GREEN pot to 1:00 which is OFF. What you would lose though is the down low horsepower and torque most people are trying to gain. Without turning the GREEN pot off you would end up in the "tug of war" which Hopple mentioned. This causes horrible drivability and could lead to throwing engine lights.
     
  7. flhtcrp

    flhtcrp New Member

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    The cobra system has one for o2 sensors does it work different? Thanks for replys just learning
     
  8. Hoople

    Hoople Account Removed

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    Just wondering,,why do you want to utilize the o2 sensors?
     
  9. flhtcrp

    flhtcrp New Member

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    Want to keep the o2 sensors to help out with fuel mileage