DTC Description
WARNING: This page is about a different car, the 2021 Kia Seltos. However, it is still accessible from the selected car via links, so may be relevant.
The ECM/PCM calculates oscillation size of rear HO2S signal which represents catalyst conversion properties. This oscillation size will determine if catalyst conversion is low due to aging or poisoning from leaded fuel or misfiring. The ECM/PCM sets P042000 if the average of calculated oscillation size of rear HO2S signal during predetermined duration is higher than the predetermined threshold.