Heated oxygen sensor (Discovery 1)

Signal Check - Figure 24

Technical conditions

Contacts	Voltage	Fuel-air mixture
2 and mass	Pulsating 0.5-1.0 V	Normal
2 and mass	0.05 V	Poor thing
2 and mass	1.0 V	Rich

Warm up the engine to operating temperature. Turn off the ignition.

Without disconnecting the electrical connector, remove the protective cover.

Start the engine.

Maintain the speed at 1800 rpm.

Measure the voltage between the sensor contact and ground.

Check the second oxygen sensor.