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Knock sensor

Discussion in '3rd Gen 4Runners (1996-2002)' started by Scott7, Feb 18, 2021.

  1. Feb 18, 2021 at 11:00 AM
    #1
    Scott7

    Scott7 [OP] New Member

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    I have had the knock sensors and wiring harness replaced twice but the “check engine” light stays on showing the codes for knock sensors. The mechanic says there’s nothing more he can do. Any ideas?
     
  2. Feb 18, 2021 at 11:08 AM
    #2
    Mohoman

    Mohoman New Member

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    I had this issues with my 3.4... turns out the knock sensor wire wasn't plugged in properly.

    Not taking a stab at your mechanic here but maybe check the wiring yourself? Cheers and good luck!
     
    Scott7[OP] likes this.
  3. Feb 18, 2021 at 11:14 AM
    #3
    Scott7

    Scott7 [OP] New Member

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    Thanks
    Not being mechanically minded, where would I look for that wire and how would I know if it’s plugged in wrong?
     
  4. Feb 18, 2021 at 12:04 PM
    #4
    mem4runner

    mem4runner New Member

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  5. Feb 18, 2021 at 12:59 PM
    #5
    negusm

    negusm New Member

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    I think the knock sensors require the removal of the entire intake plenum at least.

    What codes do you have exactly?

    I would get a mechanic that either specializes in Toyotas or is better at electrical problems. Your mechanic needs to find the problem, not just replace stuff and hope it works. That's what I do...but I'm a rank amateur.
     
  6. Feb 18, 2021 at 1:46 PM
    #6
    Mohoman

    Mohoman New Member

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    I'm not sure if its the entire plenum or the upper plenum.

    I was also just to post the same video @mem4runner posted.

    Some people here have expansive knowledge on 4runners and tacoma. I am not one of those people however, youtube can be a fantastic source! Working on a vehicle can be daunting but, the satisfaction at the end of the day is like no other!

    Hope you were able to find some direction!
    Cheers

    Edited: Correction, the entire plenum does need to come off.
    this video is a little easier for me to see

    https://www.youtube.com/watch?v=n7dkEKHUVOg
     
    mem4runner likes this.
  7. Feb 18, 2021 at 8:00 PM
    #7
    treyus30

    treyus30 New Member

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    Try premium gas.
    Last time timing belt was changed? Timing could be off.
     

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