Condition 1

WARNING: This page is about a different car, the 2006 Buick LaCrosse and 2006 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.

Before the ECM can report DTC P0135 failed, DTCs P0030, P0031, P0032, P0101, P0102, P0103, P0121, P0122, P0123, P0130, P0131, P0132, P0221, P0222, P0223, P0335, P0336, P0338, P167A, P2237, P2243 and P2251 must run and pass.
The ignition 1 voltage is between 10.5-18 volts.
The HO2S is at operating temperature for more than 50 seconds.
The time after decel fuel cut-off is more than 53 seconds.
The HO2S heater is commanded ON to 100 percent.
The calculated exhaust temperature is more than 550°C (1,022°F).
The ECM internal sensing element resistance test is enabled.
DTC P0135 runs continuously once the above conditions are met for 1 minute.