2003 Hyundai Santa Fe Q&A

2003 Hyundai Santa Fe Question: Check Engine Code P0421

What does code P0421 indicate that I should have repaired? -
Answer 1
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 -
Answer 2
read it somewhere in the manual.timing belt i think. -
Comment 1
why is it so important to change the timing belt????? -