P0135 or P0155

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.

Before the ECM can report DTC P0135 or P0155 failed, P0030, P0031, P0032, P0050, P0051, and P0052 must run and pass.
DTC P0130, P0131, P0132, P0134, P0150, P0151, P0152, or P0154 is not set.
The engine is operating.
The ignition voltage is 10-18 volts.
The intake air temperature (IAT) is greater than -30°C (-22°F).
After the previous ignition cycle the engine OFF time was greater than 2 minutes, 0 seconds for LLT.
The calculated exhaust temperature is less than 524°C (975°F).
The engine is not in decel fuel cut-off (DFCO).
The HO2S 1 is at operating temperature for greater than 10 seconds.
The internal HO2S 1 resistance is less than 10,000 ohms.
DTCs P0135 and P0155 run continuously once the above conditions are met for approximately 100 seconds.