DTC: P1166

Search Bulletins/Recalls for P1166

Trouble diagnosis name: Heated oxygen sensor 2 minimum voltage monitoring (Bank 2)

Component Description

The heated oxygen sensor 2, after three way catalyst, monitors the oxygen level in the exhaust gas on each bank.

Even if switching characteristics of the heated oxygen sensor 1 are shifted, the air fuel ratio is controlled to stoichiometric, by the signal from the heated oxygen sensor 2.

This sensor is made of ceramic zirconia. The zirconia generates voltage from approximately 1V in richer conditions to 0V in leaner conditions.

Under normal conditions the heated oxygen sensor 2 is not used for engine control operation.

DTC detecting condition:

• The minimum voltage from the sensor is not reached to the specified voltage.

Possible cause:

• Harness or connectors (The sensor circuit is open or shorted)
• Heated oxygen sensor 2
• Fuel pressure
• Injectors