This time, the owner of N53 approached me. After the repair of the NOx system, the situation has improved, but the car still switches off the Stratified charge, and sometimes vibration can be felt…
The owner claims that the car has a well-known history. All documentation, which confirms that the dealer has replaced all injectors in the Year 2010 and Year 2013, is stored. Sounds good – the injectors, replaced in 2013, should be of the 11th release (the actual release).
Hoping that there would not be many problems, I started to check diagnostics data.

As we see, the situation with the injectors – a complete nightmare!
a. injector No.2 – electrical problems;
b. it also leaks catastrophically in idle, the injector No.4 – strongly drips in idle;
c. injectors No. 2, 3, 4, and 6 have inadequate flowrate adaptations in Stratified charge;
d. injector No.2 has abnormal flowrate adaptations in Homogeneous mode, data of other injectors – on the question (they should be repeatedly evaluated after replacing injector No.2).
And finally – fuel mixture data after warm start (this time, I did not even ask to send cold start data):

Lambda by banks: 1.20 and 0.82. Offset LTFT in the 1st bank – 1.50. Complete crash!
But the car has (repeatedly) installed new injectors (in the Year 2013)! What could have happened to them? I asked the owner to send me the pictures of the injectors.

My conclusions:
a. all injectors are genuine BMW injectors;
b. injectors No.3, 4, 5, and 6 are of one batch;
c. injectors No.1 and 2 are of different batches.

In a typical scenario, the exchange of the injectors happens as follows:
a. the dealer informs BMW AG regarding the recall case;
b. BMW AG sends a full set of new injectors;
c. the dealer replaces injectors, and the old ones are placed on the shelf (till the decision of BMW AG what to do with them – send them to the expertise, refurbish or throw them in the waste bin).

It is clear that this time, the scenario was different. There are injectors of 3 different batches. The oldest injector at the time of replacement was around one-and-a-half years old. For me, it seems double suspicious that exactly 4 injectors are of the same batch. It is a large possibility that the set of injectors from the N43 series engine was installed in this engine. So – they were already used at the moment of the installation. The injector from the 1st cylinder – a one-and-a-half-year-old one – obviously was already used in any scenario.
In any case – the story regarding the dealer replacing injectors and “everything was perfect till yesterday” burst into the air.
Unfortunately, the story regarding the dealer burst, too. It turns out that this replacement is not confirmed in the documents, but – the previous owner of the vehicle has told so.
Why the initial story was so convincing? It is possible that the now-owner of the car tried to avoid the scenario “replace all injectors, and then let’s see further”. Such tricks don’t give anything – I base my decisions on live data, and I am not asking to replace everything in a row. This time, live data says that these injectors have experienced “cleaning” and “testing” with a very dirty cleaning liquid – this is the only way to explain their completely incorrect performance.
Yes, the injector of the 2nd cylinder gives fundamental problems, but the other ones are very far from a correct performance and will not “survive” the upcoming winter.