where are the diagnostic proceedures mentioned in reference to DTC0421 on 2003 Kia Optima

the blog mentions there is a diagnostic proceedure to find out if the catalytic converter is bad, I was unable to find it

by in Belton, TX on June 18, 2013
1 answer
ANSWER by , June 18, 2013
TRY WWW.ALLDATADIY.COM