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Air/Fuel ratio is 13.9. Should it be 14.7?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by briank101, Jul 22, 2013.

  1. briank101

    briank101 Member

    Joined:
    Jun 9, 2012
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    Location:
    Western Chicagoland
    Vehicle:
    2010 Prius
    Model:
    II
    Reading the OBD II for air/fuel ratio using Torque app, my air/fuel ratio is running between 13.9 and 14. Is this due to measurement error calculation from the MAF sensor and injector duty pulse width/frequency values? Or is it that the fuel injectors may be dirty/clogged and that the mixture in the cylinder is not atomizing fully, so the O2 sensors are telling the ECU to inject extra fuel to compensate for what would otherwise be lean pockets. Mileage is 103K miles.

    Any advice, appreciated.
     
    #1 briank101, Jul 22, 2013
  2. briank101

    briank101 Member

    Joined:
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    Location:
    Western Chicagoland
    Vehicle:
    2010 Prius
    Model:
    II
    Bump
     
    #2 briank101, Jul 23, 2013
  3. Muzzman1

    Muzzman1 Member

    Joined:
    Feb 17, 2012
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    Location:
    So Cal
    Vehicle:
    2012 Prius
    Model:
    Five
    I know that in a typical (dyno tuning) setting, the only time I've ever seen stochiometric 14.7 is during an idle. Other times you will rarely see anything as high as 14.7 as that is considered lean under load (depending on volumetric efficiency of the motor)
    I definitely consider 13.9-14 about perfect considering the atkins cycle in our Prius'.
     
    #3 Muzzman1, Jul 23, 2013
    briank101 likes this.
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