Where is the bank 1 sensor 1 2006 Nissan Quest located?

The bank 1 sensor 1 O2 sensor on a 2006 Nissan Quest is located on the exhaust manifold, upstream of the catalytic converter. It is positioned on the side of the engine that corresponds to cylinder bank 1, which is the side with cylinders 1, 2, and 3. To access it, you may need to lift the vehicle and potentially remove any obstructions in the way.