Conditions for Running the DTC

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

Before the ECM can report DTC P2231 failed, DTCs P0030, P0031, P0032, P0053, P0101, P0102, P0103, P0130, and P0135, and P167A must run and pass.
The HO2S heater control is enabled.
The HO2S heater duty cycle is more than 5 percent.
The HO2S heater is at operating temperature for more than 10 seconds.
The ECM does not detect a misfire condition.
The fuel injectors are enabled.
The ignition 1 voltage is between 10.5-18.0 volts.
The calculated exhaust temperature is less than 800°C (1,472°F).
The volumetric efficiency is steady within 3 percent of the air flow into the engine for 10 ms.
DTC P2231 runs continuously once the above conditions are met.