04 Liberty Bank 2 Too lean.......

Discussion in 'KJ General Discussion' started by Davidvan326, Jul 4, 2020.

  1. Davidvan326

    Davidvan326 New Member

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    I have a 2004 Jeep liberty with 3.7 L engine. I have had a bank 2 too lean issue for quite some time now. I have massive quantities of unburnt fuel coming out the exhaust. I have checked everything under the sun, with the exception of the computer. Is there a way to check the computer without buying a replacement?

    FYI.......all new O2 sensors, all injectors cleaned and functioning, all coil packs firing, pull valve covers to check for rocker arms engaged, checked for Vacuum leaks, fuel pressure is good, don’t know what else to try.

    Thanks
    David
     
  2. 03GoingStrong

    03GoingStrong Full Access Member

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  3. LibertyTC

    LibertyTC Well-Known Member Staff Member Moderator

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    With mega un burnt fuel should it not be a rich condition? Engine light on? What are the code #s ?
    You replaced the 02 sensors, with what brand ? Jeep only likes NGK/NTK 02 sensors.
     
  4. Davidvan326

    Davidvan326 New Member

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    Bank 2 is showing lean..... code P0174.... so computer is dumping fuel into cylinders at full flow to try and compensate..... fuel is getting there... Just not burning. (I’m assuming it just too rich to burn it all) Coils are firing... plugs are properly gapped and . NTK sensors.... I’ve tried swapping sensor around (thinking one of the new ones my be bad...). Still runs rough... smells crazy rich and throwing P0174 (bank 2 Lean)
     
  5. DadOSix

    DadOSix Full Access Member

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    Couple of thoughts:

    oem/ ngk sensors?

    1- wiring at the bank 02 sensor. Frayed, shorted?
    2 - are these upstream sensors (before cat) or downstream?
    3 - did you try to swap right to left (assuming the sensors are the same?
    4 - do you have a scan tool that shows your fuel trims?
    5 - fuel rail pressure ? Too low = lean. (I think it would show on both banks though)
    6 - vacuum leak? (Too much air = lean)