Conditions for Running the DTC

WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.

Before the ECM can report DTC P2243 failed, DTC P0030, P0031, P0032, and P0135 must run and pass.
The engine is operating.
The ignition 1 voltage is between 11-18 volts.
The internal HO2S sensing element resistance is greater than 570 ohms.
The HO2S heater is at operating temperature for greater than 20 seconds.
DTC P2243 runs continuously once the above conditions are met for greater than 2 seconds.