Diagnostic code interpritations

Discussion in 'General Motoring' started by John, Oct 12, 2006.

  1. John

    John Guest

    Recently, on my 99 Civic EX I've replaced the exhaust from the
    catylitic converter onward and also replaced all of the exhaust gaskets
    and nuts/bolts, etc. During this unlikely hellish event I had to
    resort to a hacksaw and a hammer to free several bolts, the worst of
    which were the pre-cat. bolts. My engine light came on the next day.

    As a consequence of my methods, I nicked one of the wires going to the
    pre-cat O2 sensor, forgot to tape it up and drove for a couple weeks.
    When re-fueling, I noticed my gas mileage dropped from 38mph to 22mph.
    Thought it was a fluke, drove another week, filled up and calculated
    the same milage. (Yeah, not too smart to drive it under these
    conditions, but I had back problems that arose because I'd spent all of
    a Saturday under the car trying to fix it, that prevented me from
    getting under it again.)

    I then patched up the wire (it was only a nick) and searched for any
    other problems. Everything looked fine. I then reset the engine code
    by unplugging the negative battery terminal.

    Still same mileage and the light re-appeared. Now I assume, with all
    that banging going on I probably ruined my pre-cat O2 sensor (It's 120K
    old anyways). To be sure, I jumped the wire connections to read the
    code and only got a
    blink.............blink.............blink......etc... I watched it
    until it consistantly and equally until it blinked 65 times. No short
    blinks, no fast ones, just a constantly slow blink every 3 seconds or
    so.

    What's this tell me?

    P.S. I am aware that if it is the O2 sensor and I continue to run the
    car this fuel rich I will plug the catylitic converter. I have been
    trying to avoid driving the car since this problem has come about. I
    just don't want to buy a $185 sensor until I'm damn sure.

    Any ideas?,
    John
     
    John, Oct 12, 2006
    #1
  2. ----------------------------------------

    Too much banging could have trashed the CAT. It is made of GLASS, after
    all. That's why it's wrapped in steel wool and asbestos inside to
    protect it from shocks.

    'Curly'
     
    'Curly Q. Links', Oct 12, 2006
    #2
  3. John

    TeGGeR® Guest



    That's a code 1. Oxygen sensor.

    However... The MIL flash code is ROUGH. to get the EXACT OBD-II code,
    you need to have the code read with a proper OBD-II reader. The OBD code
    consists of a letter and four numbers.

    AutoZone or PartSource will read the code for free. Report it back here.
     
    TeGGeR®, Oct 13, 2006
    #3
  4. John

    TeGGeR® Guest


    The core is actually made of alumina ceramic. It's pretty robust and will
    tolerate a considerable amount of abuse. The exhaust pulses themselves are
    very punishing to the cat.
     
    TeGGeR®, Oct 13, 2006
    #4
  5. John

    Matt Ion Guest

    Not to mention getting banged up against the occaisional corb or speed bump...
    cats necessarily need to be pretty damn durable.
     
    Matt Ion, Oct 13, 2006
    #5
  6. John

    Matt Ion Guest

    Er... CURB.
     
    Matt Ion, Oct 13, 2006
    #6
  7. John

    TeGGeR® Guest



    Unless you're in jolly old Englend, in which case it's "kerb".
     
    TeGGeR®, Oct 14, 2006
    #7
  8. John

    John Guest

    Right you are. Advanced Auto Parts let me borrow their OBD-11 reader
    and it reported a code:

    P0131
    O2 sensor
    Circuit Low Volts
    (Bank 1 Sensor 1)

    Ordering a new primary sensor online today. Thanks.

    John
     
    John, Oct 15, 2006
    #8
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