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P0420 Code

Discussion in '1st Gen. Tacomas (1995-2004)' started by flesheatingvirus, Jul 17, 2008.

  1. Jul 17, 2008 at 8:52 AM
    #1
    flesheatingvirus

    flesheatingvirus [OP] Well-Known Member

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    ABQ, NM
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    2016 TRD-OR 4x4AT Access Cab - Magnetic Gray
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    My CEL just came on in my 96 Taco 2.4L. According to Advanced Auto, it is the P0420 - Catalyst Efficiency below threshold bank 1. What the heck does that mean? From what I gather, it could be an exhaust manifold leak. The whole pipe up to the manifold, and the catalytic converter are new. The converter was stolen off it at the dealer lot, and he had them replaced. I fixed some pin holes a few weeks ago on some of the welds, but I didn't see anything major. I do hear a hissing sound under the hood when it is running, but I thought that it was the intake/throttle body. I'm going to see if I can find any cracks in the exhaust manifold. Any other ideas?
     
  2. Jul 17, 2008 at 9:10 AM
    #2
    tacomaracing

    tacomaracing tacomaracing

    Joined:
    Jun 15, 2008
    Member:
    #7329
    Messages:
    59
    GEORGIA
    Vehicle:
    2005 toyota tacoma 2wd 2.7L
    AFE stage 2 intake,heavley ported throttle body,one of the gas buddys off ebay,fitch fuel catalyst,electric fan and relay kit,oil catch can,gibson exhaust,magnaflow catalytic converters and the spark plug non fouler no CEL light,wraped exhaust manifold,wideband o2(innovate),relocated IAT.
    what brand is the converter you put back on there.. evidently it has higher flow rates then the ECU has parameters for witch leads to a cel light... the down stream o2 sees different then what the up-stream does,so the ECU thanks the converter is shot:fenforcer:
     
  3. Jul 17, 2008 at 9:15 AM
    #3
    flesheatingvirus

    flesheatingvirus [OP] Well-Known Member

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    ABQ, NM
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    2016 TRD-OR 4x4AT Access Cab - Magnetic Gray
    Tech Package
    I removed the manifold heat shield and:

    [​IMG]

    I guess I'll be making a trip to an exhaust shop. Can it be fixed? or should I have it replaced?

    I don't know about the converter. It just has numbers/letters stamped on the bottom.
     
  4. Jul 17, 2008 at 11:30 AM
    #4
    tacomaracing

    tacomaracing tacomaracing

    Joined:
    Jun 15, 2008
    Member:
    #7329
    Messages:
    59
    GEORGIA
    Vehicle:
    2005 toyota tacoma 2wd 2.7L
    AFE stage 2 intake,heavley ported throttle body,one of the gas buddys off ebay,fitch fuel catalyst,electric fan and relay kit,oil catch can,gibson exhaust,magnaflow catalytic converters and the spark plug non fouler no CEL light,wraped exhaust manifold,wideband o2(innovate),relocated IAT.
    i have seen headers Farley cheap for that model on sites.. and yeah it can be fixed takes a little talent to weld cast tho:D
     
  5. Jul 17, 2008 at 11:34 AM
    #5
    tacomaracing

    tacomaracing tacomaracing

    Joined:
    Jun 15, 2008
    Member:
    #7329
    Messages:
    59
    GEORGIA
    Vehicle:
    2005 toyota tacoma 2wd 2.7L
    AFE stage 2 intake,heavley ported throttle body,one of the gas buddys off ebay,fitch fuel catalyst,electric fan and relay kit,oil catch can,gibson exhaust,magnaflow catalytic converters and the spark plug non fouler no CEL light,wraped exhaust manifold,wideband o2(innovate),relocated IAT.
  6. Jul 17, 2008 at 11:05 PM
    #6
    flesheatingvirus

    flesheatingvirus [OP] Well-Known Member

    Joined:
    Jun 25, 2008
    Member:
    #7570
    Messages:
    278
    Gender:
    Male
    ABQ, NM
    Vehicle:
    2016 TRD-OR 4x4AT Access Cab - Magnetic Gray
    Tech Package
    Ok, so I replaced the manifold. When I have a buddy put his hand over the tail pipe so I can check for leaks I hear two things. First, there is a leak where the manifold bolts to the exhaust pipe. One of the donut gaskets may be off, or maybe we didn't tighten it enough. I'll check that next. Also, the rear end of the muffler leaks very badly when we do this. It is coming out around where the pipe leaves the back of the muffler. It is not a welded joint, but looks like the pipe is stuck into the muffler. Is that normal? The muffler is fairly new.
     
  7. Jul 18, 2008 at 9:45 AM
    #7
    tacomaracing

    tacomaracing tacomaracing

    Joined:
    Jun 15, 2008
    Member:
    #7329
    Messages:
    59
    GEORGIA
    Vehicle:
    2005 toyota tacoma 2wd 2.7L
    AFE stage 2 intake,heavley ported throttle body,one of the gas buddys off ebay,fitch fuel catalyst,electric fan and relay kit,oil catch can,gibson exhaust,magnaflow catalytic converters and the spark plug non fouler no CEL light,wraped exhaust manifold,wideband o2(innovate),relocated IAT.
    yeah,thats odd.. put the welder on it!!!! weld every hole,crack,anything that leaks or a hole new exhaust system-hope not thats pricey:(
     
  8. Jul 18, 2008 at 11:41 AM
    #8
    flesheatingvirus

    flesheatingvirus [OP] Well-Known Member

    Joined:
    Jun 25, 2008
    Member:
    #7570
    Messages:
    278
    Gender:
    Male
    ABQ, NM
    Vehicle:
    2016 TRD-OR 4x4AT Access Cab - Magnetic Gray
    Tech Package
    I had the muffler sealed up today. It only cost me 10 bucks! I also changed the fuel filter (that was fun), filled the tires, put in synthetic Mobile 1, changed the spark plugs and air filter. Now we'll see what kind of mileage I get. I was getting about 20mpg. I'd like to see if i can get any more than that.
     
  9. Jul 18, 2008 at 11:47 AM
    #9
    tacomaracing

    tacomaracing tacomaracing

    Joined:
    Jun 15, 2008
    Member:
    #7329
    Messages:
    59
    GEORGIA
    Vehicle:
    2005 toyota tacoma 2wd 2.7L
    AFE stage 2 intake,heavley ported throttle body,one of the gas buddys off ebay,fitch fuel catalyst,electric fan and relay kit,oil catch can,gibson exhaust,magnaflow catalytic converters and the spark plug non fouler no CEL light,wraped exhaust manifold,wideband o2(innovate),relocated IAT.
    thats great,hope everything works,those fuel filters BLOW---so hard to get to!!!!!! the 05s don't have one :cool:
     
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