p0606 error after cat converter and lambda replacement

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by LuckyLemon335, Aug 12, 2019.

  1. LuckyLemon335

    LuckyLemon335 New Member

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    Hi all, my cat converter and lambda were stolen back in February 2019. Cat was replaced with aftermarket one and denso lambda.

    All was fine, but then after about 1000 miles check engine error popped up with code p0606. Error comes on and off randomly about twice a week. I tried replacing lambda with no success. It goes like this for a few months now, average consumption is about 50-60mpg.

    Did anyone face this problem? What would be steps for troubleshooting? Thanks in advance
     
    #1 LuckyLemon335, Aug 12, 2019
  2. SFO

    SFO Senior Member

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    What does the odometer currently read?

    When was the last time the plugs were changed?

    Have you ever serviced the injectors?
     
    #2 SFO, Aug 12, 2019
  3. LuckyLemon335

    LuckyLemon335 New Member

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    120,000 miles
    I got car in 2015 when it was 83,000 (2015) and did not change plugs, so not sure when they were last changed.
    I have never serviced the injector.
     
    #3 LuckyLemon335, Aug 12, 2019
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    DTC P0606 means that the engine ECU has an internal fault. There are two CPUs within, and apparently they disagree with regards to how much the throttle position should be or how much the accelerator pedal is depressed; hence one or the other has a fault. The fix is to replace the engine ECU which is located behind the glove compartment (at least that is the location for LHD vehicles.)
     
    #4 Patrick Wong, Aug 12, 2019
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  5. LuckyLemon335

    LuckyLemon335 New Member

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    Okay, thank you. So this is completely unrelated to replacement of cat converter and lambda?
    (It find it strange that this error appeared very shortly after lambda and cat replacement.)
     
    #5 LuckyLemon335, Aug 13, 2019
  6. SFO

    SFO Senior Member

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    My bad with the prior posting. Must've confused your post with a P0420 post.

    You mentioned using a Denso lambda sensor, which part # was installed downstream?

    You might also check for exhaust leaks, and faulty electrical connections.
     
    #6 SFO, Aug 13, 2019
  7. Paul Schenck

    Paul Schenck Active Member

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    I’m ready to swap an engine ecu from a 2006 into my 2005 the part #s don’t look identical. Any advice??


    iPhone ?
     
    #7 Paul Schenck, Sep 13, 2019
  8. Patrick Wong

    Patrick Wong DIY Enthusiast

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    It will not be that easy to remove the engine ECU. My suggestion is that if possible, you try to remove the wiring harness connectors while the ECU remains in place, and see if you can hook up the replacement ECU to verify that the replacement will work.

    Once you've determined that the replacement is working better than the original, then go to the effort to take apart the dashboard to remove the original ECU and install the replacement.
     
    #8 Patrick Wong, Sep 13, 2019
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  9. Skibob

    Skibob Senior Member

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    My advice is don’t do it. If the numbers don’t match it probably won’t work
     
    #9 Skibob, Sep 19, 2019
  10. AndyFromWI

    AndyFromWI Junior Member

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    I had a similar problem after my Catalytic converter was stolen. I replaced it with an ArticExhaust from ebay. I also replaced the downstream 02 sensor with an Denso (without the plug), wired it in, but was getting P0138 codes, then later P0138, P0139 and the dreaded p0606 code.
    After some research I had a feeling something was not right with my 02 sensor, so I got another Denso but with the plug, I can't believe how easy it was to pull up the passenger floor matt and get access to the plug. With the new 02 Sensor, all codes have gone away. Only have a few hundred miles on it so far, but the codes are gone.
    -andy
     
    #10 AndyFromWI, Apr 13, 2020
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  11. Paul Schenck

    Paul Schenck Active Member

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    I learned you were right. It appears to work however the Fuel pressure values on the Evap system are different for the 2006 and it turns on the check engine light and throws fuel pressure sensors codes


    iPhone ?
     
    #11 Paul Schenck, May 7, 2020
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