Performance Check

Run the engine at 2500 RPM for two minutes, to heat up the O2 sensor.
Check the voltage of the sensor output: Alternates between less than 0.4V at feed back engine conditions and in excess of 0.5V, see graph.

Fig 1: Checking Voltage Of Sensor Output

These voltages are for reference only.
Check that cycle of the upstream sensor output is in accordance with the appropriate pinpoint test.
Check that cycle of the downstream sensor output is in accordance with the appropriate pinpoint test.