Results 1 to 6 of 6

Thread: AFV cylinder difference keeps running out of control.

  1. #1
    Junior Member
    Join Date
    Jul 2015
    Posts
    1

    AFV cylinder difference keeps running out of control.

    Hey!

    Bought a 2009 1125cr with 7230km

    It had a K&N airfilter, Exan Slip-on muffler and a Power Commander 5.
    Both 02 sensors where disconnected.

    Bike ran like **** and I decided to rip out the PC...

    Plugged everything back togheter and did a TPS reset.

    Went out on a 175km run and suddenly the engine light came on.
    Pulled over and a friend plugged his buellthooth in.

    Error code ”AFV cylinder difference too high”
    Front fuel adapt was set to 147% and rear 87%.

    Reseted it to 100/100 and clear the error codes, made a TPS-reset, value 2.0

    When I got home I checked the diagnostics mode and found out that the AFV is it is on it`s way again..

    TPS-precent 1.5
    Voltage 0.5

    Front 02 sensor voltage 0.4
    Rear 02 sensor voltage 0.4

    Front adapt fuel 109.5
    Rear adapt fuel 85.5

    I`m confused since this should at least be the other way around?

    Have cleaned the 02 sensor connectors and double checked that they are plugged in correctly..

    Any advice?

  2. #2
    Senior Member Cooter's Avatar
    Join Date
    Dec 2012
    Location
    Crawling up your skirt
    Posts
    5,713
    "Both O2 sensors"? On an '09? If the header and sensor were added, you can use the ECMDroid program you have (with the Buelltooth) to make sure "front O2" is enabled.

    But first, proper diagnosis is to continue your effort to make it stock take the add-on Power Commander thing off the bike. They are completely unnecessary (for years) now that the stock ECM has been jail-broken. Any tune you get for a similar muffler will most likely be MUCH better than any add-on P.C. thing that just fakes the sensor inputs.

  3. #3
    Senior Member Mesozoic's Avatar
    Join Date
    Jul 2008
    Location
    Tucson, AZ
    Posts
    193
    Perhaps your fuel maps have been altered and/or the exhaust/airflow upgrades require remapping to the point that the ECM is making note of it.

  4. #4
    Senior Member d_adams's Avatar
    Join Date
    Apr 2010
    Location
    Just outside of St. Louis
    Posts
    3,432
    "Exan Slip-on muffler" <== not a very common exhaust. Is there even a proper calibration for it?

    "Both 02 sensors where disconnected." Bad Idea. Plain and simple.

    "Error code ”AFV cylinder difference too high”
    Front fuel adapt was set to 147% and rear 87%. " Well, this right here tells you that it is NOT correctly tuned or calibrated. The front cylinder is calling for more than 50% more fuel than it was originally designed for, this is due to a DRASTIC change in air flow as seen by the engine.


    Sounds like the O2 sensors are working just fine, you need to do one of 2 things. Either map the ecm correctly with widebands (I'd suggest 13:1 air/fuel under a hard load, maybe 14.5:1 at cruise as a good starting point) or put everything back to stock (exhaust, ecm, intake mods) and call it a day.
    Narrowband tuning with ecmdroid or whatever is just setting you up to fail. Narrowbands simply cannot supply you with the correct information regarding as to how the engine is really running. Period.

  5. #5
    AFV is computed in closed loop operation, and there a narrowband O2 sensor will work perfectly well.

  6. #6
    Senior Member Cooter's Avatar
    Join Date
    Dec 2012
    Location
    Crawling up your skirt
    Posts
    5,713
    Go back to stock. If the tune can be changed to a known stock tune, that would be my step one in diagnosis.

    Then you will know if you need to modify the ECM further, or look for something mechanical, like an intake seal.



Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •