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2005 prius cel on going problem

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by boostrd, Apr 1, 2014.

  1. boostrd

    boostrd Junior Member

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    Location:
    south mills nc
    Vehicle:
    2005 Prius
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    N/A
    hey everyone need some help with my 2005 prius. the car is pulling three codes misfire cyl1, misfire cyl2, and multiple misfires. the car has over 450000 miles on it and runs like a dream. i just replaced they spark plugs and the coil packs in each cylinder. the cel codes are still there after clearing them. anyone know of anything to do or if there is a problem someone has fixed already? i am willing to replace the fuel injectors but just seems weird that two of them would go out like that together. help!

    oh and after clearing the codes they will stay off for a few days then come back. car seems to run fine and doesnt hesitate
     
    #1 boostrd, Apr 1, 2014
  2. mikefocke

    mikefocke Prius v Three 2012, Avalon 2011

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    And you have read the codes and they translate to what? First rule of diagnosis is to answer the question ... what are the codes. Then maybe someone can point you towards what they are telling you and what does the service manual say they refer
     
    #2 mikefocke, Apr 1, 2014
  3. boostrd

    boostrd Junior Member

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    yeah got it bud i re-posted and it says in my post what the codes are. misfires cyl1 and 2 and multiple misfires. sorry i don't have the exact numbers of them, don't really know that's necessary but ill work on it.
     
    #3 boostrd, Apr 1, 2014
  4. mikefocke

    mikefocke Prius v Three 2012, Avalon 2011

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    Faults trigger CELs and when you turn the CEL off typically the car goes through several cycles of use where it learns the new values and adapts the norms, then compares them to some preset limits and alerts if there are an excessive number of readings that are out of bounds. Which explains the 'stays off for a few days' part of what you are seeing. And why it comes back, the cause of the fault is still there.

    Most service manuals give a list of possible causes and even sometimes a flow chart that tells you to do this first, then check and if not then do this next and check again etc.

    I just looked at another brand's service manual for the equivalent of Cyl-1 Misfire and it cites ignition but also fault in the O2 sensor system wiring or sensor itself causing rich or lean. It says this fault is typically stored based on a signal from the flywheel located inductive sensors. If the engine rotation speed is uneven for a part of a revolution, then the computer knows that there is something wrong in the cylinder which was supposed to be driving that portion of the revolution.
     
    #4 mikefocke, Apr 1, 2014
  5. boostrd

    boostrd Junior Member

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    Location:
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    Vehicle:
    2005 Prius
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    N/A
    so what your sating is that the o2 sensor could be making the 1 cyl run lean or rich throwing off the ratio of air to fuel causeing a misfire, which throws the system out of balance there for the 2nd cyl misfires?
     
    #5 boostrd, Apr 1, 2014
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