All I could find right now is a schematic of a 2007 Saturn Outlook. Bank 2 Sensor 1 shows the sensor to be near the top of the exhaust pipe that comes down the side of the engine and bends under the engine and towards the rear. The Bank 2 is actually towards the radiator and is also called the left side of the engine. Bank 2 Sensor 2 would be near the bottom of the exhaust pipe where it starts to curve towards the rear of the car.
Bank 1 is near the firewall, and is also called the right side of the engine.
I would think the terminology has not changed for the 2009, even though you have the D.I. engine.
Thanks - that is very helpful. I was under the impression that cylinder 1 (usually corresponding to "bank 1") on the GM 3.6 is the upper left cylinder at the top of motor, which would mean the opposite, but I am trusting your schematic as the firing order should not change with DI.
If it is the top one on the radiator side, it is dead simple to get to so yes, AA/78U, I plan on doing it myself.
Anybody have a recommendation on which brand to get? I have heard both good/bad about Walker, Bosch is expensive and Denso looks like garbage (but I could be wrong)