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Fault Codes P0161 and P0158 - M54 330i

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Lets start by saying I was on a very very long private road, where I reached speeds of up to 115mph. Shortly after the CEL came up, and the car was down by 50% power and was vibrating. 


I initial thought I had blown a coil, and was down a cylinder or two. Shortly after I came to a stop at a set of traffic lights on a public road, which is when the CEL went off and the car resumed to normal power. Werid


I checked the codes immediately after and have codes P0161 and P0158, which both point towards bank 2 02 sensors. 


I previously had more codes, but found that I had an intake and fuel filter vacuum leak, which I have sorted, along with cleaning the ICV and TB.


There is a possibility I still may have a vacuum leak from VCG, but can't confirm, I also have a exhaust leak from the mid box just before the rear tail pipes.


Most of the time, my car does seem quick, especially at the bottom end, but that's not to say that it couldn't be even quicker. I currently get 25mpg, so I am not sure if this is normal or if it is over fueling. 

Mileage of my car is currently 148K with no prior evidence of the 02 sensors ever being changed. 


Now my question is... Do I actually have a single/pair of faulty 02 sensors? or is my problem elsewhere, which is leading the ECU to report a fault with the 02 sensors? 

Thanks for viewing my post and any comments that may come my way.

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Vacuum leak usually throws codes on both banks.

Do you have inpa so you can measure live values (you also get bmw specific codes you can't always see with generic readers). that will tell you if ecu is compensating by adding more fuel.

Could be a faulty coil or injector?

You could pull each plug and check if they all look the same.

Exhaust leak before the o2 sensor could also throw a code.

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Thanks Jerome, I do have INPA but was being lazy and just used a generic code reader. 


Wouldn a faulty injector or coil not cause rough running all the time? 


I can't say for 100% sure that I don't have any other exhaust leaks, but the only one I am aware is after the 02 sensors, which is the rear mid box. 


I'll keep you posted, once again thanks for your input. 

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You're injector could be marginally out of spec and only throw a code at high flow rates (I'm theorising here, this could be utter nonsense).

The coil being an electronic component may only misbehave if it gets hot and work fine at normal temps (I had a cam sensor that did that) but the ecu would still log a fault. Reading the codes with inpa also gives background of what the engine was doing when the fault occured

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