location of bank 1 sensor 1

your vehicle's oxygen sensor 1 / 1 is on the exhaust manifold. the oxygen sensor 1 / 2 is in the catalytic converter.

Heres a guide on how to change it, not vehicle specific, but will give you an idea of what to expect

https://www.2carpros.com/articles/how-to-replace-an-oxygen-sensor

See the picture attached below