What is bank 1 for Mazda 6 2004 sensor?

In a 2004 Mazda 6, "Bank 1" refers to the side of the engine that contains cylinder number one. The Bank 1 sensor typically refers to the oxygen sensor located on that side, which monitors the level of oxygen in the exhaust gases. This information is crucial for the engine control unit to adjust the air-fuel mixture for optimal combustion and emissions control. If there are issues with this sensor, it can lead to poor engine performance and increased emissions.