P0138, P0140, P0158, and P0160

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

The HO2S 2 is at operating temperature for greater than 90 seconds.
The engine is operating for greater than 1 second.
The ignition voltage is greater than 10 volts.
The calculated exhaust temperature is greater than 800°C (1472°F).
DTCs P0138 and P0158 run continuously once the above conditions are met for greater than 5 seconds.
DTCs P0140 and P0160 run continuously once the above conditions are met for greater than 60 seconds.