code p0420

Discussion in 'General Motoring' started by newman, Jun 1, 2007.

  1. newman

    newman Guest

    Autozone pulled my code today; it was P0420, indicating catalytic
    converter. The check engine light had come on the day before.

    The car has 106000 miles and the timing belt was changed last week by Honda
    dealer (complete with water pump, seals, etc).

    Is it normal for converters to fail after this mileage? The car has been
    well taken care of.

    99 Accord EX 4-cyl
    106000 miles

    The Autozone dealer recommended that if I replace converter, Honda dealer
    should do the work.
    newman, Jun 1, 2007
  2. newman

    motsco_ Guest


    P0420 Catalyst efficiency _APPEARS_ to be below threshold for more than
    three cycles. If either of the O2 sensors goes bad, the computer may
    come to the conclusion that the cat is bad.

    Any 'issues' with the engine since the dealer (recently) touched it? Do
    you use injector cleaner seasonally, has the engine ever stalled,
    especially during warm-up, do you ever get idle speed going up and down ???

    If it really _is_ the cat, you need to determine what killed it, or
    you'll soon be putting another in there. I'd get a generic cat but only
    after I made sure the O2 sensor(s) are OK.

    motsco_, Jun 1, 2007
  3. newman

    motsco_ Guest


    Here's an important one for cat health: Is the coolant reservoir full to
    the =MAX= mark, per the owner's manual? The dealer knows they have to
    fill it up any time the cooling system is apart.

    If there's air in the cooling system the computer can set the mixture /
    timing all wrong which will shoot your mileage all to pot, and wreck the
    cat. Has you mileage been exemplary since the timing belt was done?

    motsco_, Jun 1, 2007
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