Conditions for Setting the DTC

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

P2096

The post catalyst FT weighted average value is less than a calibrated value.
The DTC sets when the above condition is met for 4 seconds continuously, or for 50 seconds cumulatively.

P2177 or P2187

The long term FT weighted average value is greater than a calibrated value at idle, cruise or during acceleration.
The DTCs set when the above condition is met for 4 seconds continuously, or for 50 seconds cumulatively.