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The p0420 code few questions

Discussion in '1st Gen. Tacomas (1995-2004)' started by rll131, May 14, 2012.

  1. May 14, 2012 at 6:58 AM
    #1
    rll131

    rll131 [OP] rll131

    Joined:
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    raymond
    elkton md 21921
    Vehicle:
    2000 2.4 liter 4 banger
    I have a 2000 2.4 Tacoma code just came one. There are no exhaust leaks and the truck still runs great and I'm getting around 26-27 mpg so no loss in gas mileage. What should I start with what should I replace first I tried resetting and putting different gas popped back on about 70 miles later.

    Also I looked at the o2 sensor it was pretty dirty old looking but there was no plug I've changedno2 sensors before but there was always a plug that you just unplug this one has no plug so how would I change it and which o2'sensor do I change for this cod ethe one before the cat and after the manifold or the one after the cat and before the muffler.
     
  2. May 14, 2012 at 10:11 AM
    #2
    tan4x4

    tan4x4 Well-Known Member

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    Folsom, CA
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    99 Tacoma EC 4x4 2.7L Auto
    Bilsteins, OME 881's, 3-leaf AAL, Detroit TruTrac, 31" tires, Michelin LTX AT2, stock gears, Tranny skidplate, TC skidplate, CBI rear bumper, sliders, UltraGauge, PowerTank, CB
    Either bad sensor or bad cat. Just have to narrow it down.
    What do you mean by 'no plug'? Not connected to the harness?

    I think you can test the sensors with a resistance check.
    If either one fails that, then replace it.
     
  3. May 14, 2012 at 10:59 AM
    #3
    rll131

    rll131 [OP] rll131

    Joined:
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    elkton md 21921
    Vehicle:
    2000 2.4 liter 4 banger
    Yea there is no connecting harness on the o2 sensor behind the cat only on the one before the cat
     
  4. May 15, 2012 at 7:48 AM
    #4
    tan4x4

    tan4x4 Well-Known Member

    Joined:
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    Gender:
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    Rick
    Folsom, CA
    Vehicle:
    99 Tacoma EC 4x4 2.7L Auto
    Bilsteins, OME 881's, 3-leaf AAL, Detroit TruTrac, 31" tires, Michelin LTX AT2, stock gears, Tranny skidplate, TC skidplate, CBI rear bumper, sliders, UltraGauge, PowerTank, CB
    Well, that has got to be the problem, then.
    Is it possible that someone tried to steal your cat, and cut off
    that wire, before giving up or being scared off?

    If so, you need to re-establish the connection. There should be dangling
    wires (one from the sensor, and one from the harness nearby).
     
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