Chevrolet Q&A

Ask Your Question

1997 Chevrolet Monte Carlo Question: emmission codes



Visitor, 3.1L V6, La Porte, TX, January 22, 2011, 03:25

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

1 Answer
Flag This
  • Answer #1

    kwmk (see my shops), January 27, 2011, 12:35

    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.

    Flag This
Answer Ranks