Conditions For Setting DTC
WARNING: This page is about a different car, the 2003 Pontiac Grand Prix, 2003 Chevrolet Malibu, and 2003 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
The PCM detects that the HO2S 1 rich-to-lean transition time takes longer than 105 milliseconds or the PCM detects that the HO2S 1 lean-to-rich transition time takes longer than 95 milliseconds.