Over the winter I was getting the following codes, along with a bit of a misfire and it smelled like it was running rich. When the weather warmed up, the car started running normally again but it was still setting the codes:

• P0059 HO2S Heater Resistance Bank 2 Sensor 1
• P0155 O2 Sensor Heater Circuit Bank 2 Sensor 1
• P2197

I finally got under the car last week and replaced the driver's side front (upstream) O2 sensor. It was good for a week and the car still runs...

Codes after replacing O2 sensor