Thread: 2004 L322 4.4L V8 misfire on cylinders 1-4 but OBD code P0156 is Bank2 Sensor2 fault

Dear Members,
I have a 2004 L322 4.4L V8 that has recently started to run rough at idle (engine fault light comes on, but disappears when driving) and lacks power at normal driving speeds. Using a Carsoft i930 diagnostic tool, the following OBD fault Codes were detected:
P0000 (Electric thermostat circuit fault)
P1301 (Multiple misfire fault)
P0301, P0302, P0303, P0304 (Misfires detected on cylinders 1-4)
P0156 (O2 sensor circuit bank 2 downstream sensor. Bank 2 Sensor 2)

I would expect that if cylinders 1-4 are misfiring, the O2 sensor circuit fault would be Bank 1, not Bank 2?

Is anyone able to help me understand why these faults appear to conflict?

My next step is to replace the O2 sensors, check all the wiring and clear the fault codes to test again.

Many thanks and best regards, Greg (Cuz)

G`day ,

don`t know , depends on the cause could be 2 things the missing won`t necessarily affect O2 reading enough to register/log a fault .

The O2 telling what it is doesn`t necessarily mean it`s broken they can be tested .

Is the rough idle all the time or is it hot or cold , when does it happen .

Is the light on with the rough idle or doesn`t it matter , what revs or speed does it extinguish and does it come back on or stay off , till restart or what .

Where did you find the definition P0000 code as thermostat at best that i can find it`s suggested it`s a code to say no faults logged or a pass code .

Below is a pdf if it works it`s a manual for L322 only thing is it for the USA , CAN .MEX market so has some differences .

You will find test procedure of O2s , P codes etc , most is there

http://www.landroverweb.com/Pdf-file...ge%20Rover.pdf