Oxygen Sensor Bank 1 Sensor 1
WARNING: This page is about a different car, the 2005 Suzuki Reno and 2005 Suzuki Forenza. However, it is still accessible from the selected car via links, so may be relevant.
The Heated Oxygen Sensor 1 (HO2S1) reading represents the exhaust oxygen sensor output voltage. This voltage will fluctuate constantly between 100 mv (lean exhaust) and 900 mv (rich exhaust) when the system is operating in a Closed Loop.