O2 bank 1 sensor 2 in lumina 2008?

Howard has a good point...the 'reader' is not diagnostic. Sensor 2 is the 'downstream' one, further from the engine that the #1 sensor. 'Bank 1' usually refers to the passenger side (in the US) of the car. While the sensor might be 'repairable' , at about $60 for most units, it's not worth my time to worry about it...pull the old one out, screw the new one in...done. The auto store has a 'split socket' tool you can borrow to make it easier.