Possible causes

For Models 2005 and up:
– Faulty Air Fuel Ratio Sensor 1 Bank 2
– Air Fuel Ratio Sensor 1 Bank 2 circuit is open or shorted
– Air Fuel Ratio Sensor 1 Bank 2 circuit electrical connection

For Models before 2005:
– Faulty Heated Oxygen Sensor 1 Bank 2
– Heated Oxygen Sensor 1 Bank 2 circuit is open or shorted
– Heated Oxygen Sensor 1 Bank 2 circuit electrical connection

Tech notes

There is a service bulletin for the following models:

2005-2006 Nissan Altima
2005-2006 Nissan Altima Service Bulletin P1168 OBDII Code

2004 Nissan Maxima w/ 5 Speed Automatic Transmission
2004 Nissan Quest w/ 5 Speed Automatic Transmission
2004 Nissan Maxima, Quest Factory Service Bulletin P1168 OBDII Code

2004 Nissan Maxima w/ Manual Transmission or 4 Speed Automatic Transmission
2004 Nissan Quest w/ 4 Speed Automatic Transmission
2004 Nissan Maxima, Quest Factory Service Bulletin P1168 OBDII Code

2004 Nissan Armada
2004 Nissan Titan
2004 Nissan Armada/Titan Factory Service Bulletin P1168 OBDII Code

When is the code detected?

The closed loop control function for bank 1 does not operate even when vehicle is driving in the specified condition, the closed loop control function for bank 2 does not operate even when vehicle is driving in the specified condition.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P1168 NISSAN Description

The Engine Control Module (ECM) performs ON/OFF duty control of the Air Fuel Ratio (A/F)/Heated Oxygen Sensor 1 heater corresponding to the engine operating condition to keep the temperature of Air Fuel Ratio (A/F)/Heated Oxygen Sensor 1 element at the specified range.

NISSAN Technical Service Bulletins for P1168 code