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1997 Chevrolet Monte Carlo Question: emmission codes

 

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Visitor, 3.1L V6, La Porte, TX, January 22, 2011, 00:25

do u know what the code po121 means for 97 monte carlo 3.1 v6? or po420 on 98 merury sable?

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  • Answer #1

    kwmk (see my shops), January 27, 2011, 09:35
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     Journeyman

    The p0121 on the monte carlo is a throttle position fault. More testing would be needed to determine if the sensor is actually bad. The p0420 on the mercury is a catalytic converter fault. Most likely indicating the converter should be replaced.

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