Conditions For Setting DTC
WARNING: This page is about a different car, the 2003 Cadillac Seville and 2003 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
The PCM detects that the HO2S 1 voltage failed to switch from rich-to-lean within a 90 second monitoring period or the PCM detects that the HO2S 1 voltage failed to switch from lean-to-rich within a 90 second monitoring period.