Conditions For Setting DTC

WARNING: This page is about a different car, the 2002 Pontiac Sunfire, 2002 Pontiac Grand Am, 2002 Oldsmobile Alero, and 2002 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.

The average HO2S 1 response times are more than 875 milliseconds for rich-to-lean sweeps, or 600 milliseconds for lean-to-rich sweeps.
Sum of rich-to-lean and lean-to-rich is more than 875 milliseconds.