Conditions for Setting the DTC

WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

When the AIR pump is commanded ON, during closed loop operation and the HO2S voltages do not decrease below 222 mV for 1.5 seconds.
The short term FT does not change more than a predetermined amount.