Oxygen Sensor Diagnosis

The fuel control Heated Oxygen Sensor (HO2S 1) is diagnosed for the following conditions:
^ The heater performance-time to activity on cold start
^ A slow response
^ The response time-time to switch R/L or L/R
^ An inactive signal
^ A signal fixed high
^ A signal fixed low

The catalyst monitor Heated Oxygen Sensor (HO2S 2) is diagnosed for the following functions:
^ The heater performance-the time to activity on a cold start
^ The signal fixed low during steady state conditions or power enrichment-a hard acceleration when a rich mixture should be indicated.
^ The signal fixed high during steady state conditions or a decel fuel mode-deceleration when a lean mixture should be indicated
^ An inactive sensor-output steady at approximately 438 mV