Oxygen Sensor Bank 1 Sensor 1
WARNING: This page is about a different car, the 2008 Suzuki Reno, 2008 Suzuki Forenza, 2007 Suzuki Reno, and 2007 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.