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2003 Hyundai Santa Fe Question: Check Engine Code P0421



, 4 Cylinder, Hampton, VA, April 09, 2009, 11:19

What does code P0421 indicate that I should have repaired?

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  • Answer #1

    April 09, 2009, 12:40

    A code will never point to one item as needing replacement, it takes a diagnosis of the related systems to determine the fault. Here are some things to check for that code:
    A code P0421 may mean that one or more of the following has happened:
    * The catalytic converter is no longer functioning properly
    * An oxygen sensor is not reading (functioning) properly
    * A spark plug is fouled up

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  • Answer #2

    April 12, 2010, 09:43

    read it somewhere in the manual.timing belt i think.

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  • Reply

    , June 28, 2013, 08:24

    why is it so important to change the timing belt?????

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