P0141 and P0161
WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The ECM detects that the HO2S 2 internal resistance is greater than 650 to 1,000 ohms during a sample period of 10 HO2S 2 heater ON/OFF and OFF/ON cycles. The condition exists for greater than 10 seconds.