Conditions For Running DTC

WARNING: This page is about a different car, the 2002 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.

The engine is operating on alternative fuel.
Engine speed is greater than 500 RPM.
The engine has been operating for at least 2 minutes.
The AF ECM determines the O2S has been at operating temperature for at least 2 minutes. The engine coolant temperature must be greater than 104°F (40°C) and the calculated mass airflow must be greater than 6 grams per second for 2 minutes in order for the AF ECM to determine the O2S is at operating temperature.