Is the upstream O sensor also called the drivers or passenger side?

The upstream O2 sensor is typically located before the catalytic converter in the exhaust system, and its position is generally referred to as the "bank 1" sensor or "sensor 1." It is not specifically designated as the driver or passenger side, as this can vary by vehicle make and model. In most vehicles, the upstream sensor is on the same side as the engine bank that contains cylinder number one. Therefore, it’s essential to refer to the specific vehicle’s service manual for accurate identification.