"Service engine soon" light came on 3 weeks ago at 157,000 miles. Went to Advance Auto and read the code, and it said Bank 2, Sensor 1 was bad. So I replaced the driver side rear sensor with a brand new NTK OEM one that I got on Ebay a couple of years ago (I got a steal on two brand new OEM rear sensors). Yesterday, the light came on again. Went to Advance and read the code and it said the same thing. So this time, I replaced the passenger side rear sensor. Just curious....does anyone know how the sensors are labeled on the GVs. I assume "Bank 2" denotes rear, and I figured "Sensor 1" would be driver side, but maybe not. The service manual seems to make no distinction. Thanks in advance to anyone who knows for sure. Hopefully my light is out for good now!