Hi All -
I was tootling along the motorway the other day, and all of a sudden I got a "restricted performance" message come on screen.. a quick scan showed code P0175 - Bank 2 is too rich - I looked also at the LTFT and STFT for both banks and Bank 1 was reading STFT 0.78% and LTFT 6.25% whereas bank 2 was reading STFT 2.34% and LTFT -15.63%
Normally I am used to both banks on V engines being lean or rich, but I am unsure how to proceed with one bank being rich - Google garage suggests possible MAF malfuntion - Does anyone have an XJR X350 which they can get a MAF reading from when engine is at idle, with drive D selected ? I read that it should show about 5.1g/s, but mine is currently showing between 6.49g/s - 7g/s
Fuel pressure at idle is 53.95psi and it has a newish fuel filter.
Any input welcome!
P0175 code - (Bank 2 too rich)
Re: P0175 code - (Bank 2 too rich)
I get similar issues on my XJR but that does have sports (not recommended) cats fitted. The cats are rather less efficient than standard units and as a result Lamda sensors can`t always keep up with the running situation. This taught me that on my set up, sensor condition is vital. In my case I replaced an after cat sensor on the near side. That has helped greatly. Lambda sensor issues do cause the type of problem you are experiencing.
It strikes me you might also have a similar sensor issue perhaps caused by high mileage and sensor tiredness/dirt. Sometimes you can be lucky and just find the sensor coked up. A good manual clean up can help. I suggest you begin by running a couple of cans of Cataclean or Oxycat through the fuel tank for a couple of weeks. This will help clean out the cats and hopefully also de-gunk sensors. Both are good products.
You could also clean the MAF sensor hot wire with spray carb cleaner. Remove the sensor from the tube on the lid of the air cleaner box and examine. The hot wire should be bright silver and clear of black crank case breather gunk. It is not unusual to find gunk built up on the upstream side of the hot wire.
It is also worth going round the top of the engine and checking the condition of the small rubber vac/pressure pipes. Given age and mileage, these little 3mm internal diameter pipes rot, split or crack for a past time. Air leaks then occur and mixture control goes out of the window.
Hope that helps.
Mike K
It strikes me you might also have a similar sensor issue perhaps caused by high mileage and sensor tiredness/dirt. Sometimes you can be lucky and just find the sensor coked up. A good manual clean up can help. I suggest you begin by running a couple of cans of Cataclean or Oxycat through the fuel tank for a couple of weeks. This will help clean out the cats and hopefully also de-gunk sensors. Both are good products.
You could also clean the MAF sensor hot wire with spray carb cleaner. Remove the sensor from the tube on the lid of the air cleaner box and examine. The hot wire should be bright silver and clear of black crank case breather gunk. It is not unusual to find gunk built up on the upstream side of the hot wire.
It is also worth going round the top of the engine and checking the condition of the small rubber vac/pressure pipes. Given age and mileage, these little 3mm internal diameter pipes rot, split or crack for a past time. Air leaks then occur and mixture control goes out of the window.
Hope that helps.
Mike K
X350 Co-ordinator
2004 XJR
2004 XJR
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