The oxygen sensors, or lambda probes, tell the control unit whether the mixture is rich or lean. The car tests them and their heaters on its own, and this screen shows those results with the limits set by the manufacturer.
To follow the sensors in real time, use Live Data.
Connect with the car stopped
Connect the adapter, turn the ignition on or start the engine, and keep the car stopped.
Tap Read
On cars with the CAN protocol the tests come from OBD service 06. On older cars the app also reads service 05, where those cars keep the oxygen sensor tests. On the free plan the reading starts after a short ad.
Find the sensor
Each sensor appears by its position. B1S1 is bank 1, sensor 1: the one before the catalyst, on the side of cylinder 1. S2 is after the catalyst. Engines with a single row of cylinders only have bank 1.
- B1S1, B1S2, B2S1
- Bank and position of the sensor. S1 is before the catalyst, S2 after it.
- Within limits
- The last result is inside the limits set by the manufacturer.
- Out of limits
- The last result is outside the limits.
- Reference
- A value the car reports for information, with no limits to judge it, such as the voltage thresholds of older cars.
- See O2 sensor values in Live Data
- Opens Live Data to follow the sensors in real time.