Conditions For Running DTC

WARNING: This page is about a different car, the 2002 GMC Savana Special, 2002 GMC Savana Camper Special, 2002 GMC Savana, and 2002 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.

The engine is operating on alternative fuel.
The engine speed is more than 400 RPM.
The engine has been operating for at least 4 minutes.
The AF ECM determines the HO2S has been at operating temperature for at least 30 seconds. Operating temperature is indicated when engine coolant temperature is more than 104°F (40°C) and desired gas flow is greater than 0.3 grams per second for 30 seconds.