The owner of the N53 series engine approached me. He claims he made serious investments, including replacing all injectors with new ones. The NOx system is working, too – the NOXEM is installed.
At the same time – he has some problems.
Let’s check the error messages.

This engine has serious problems – there is no doubt! In addition, it is strange that the range of basic error messages (regarding cooling blinds and fuel mixture) can be found in the Info list! Correctly working MSD80/81 does not do that!
Further – live data, incorrect values marked with red:

What does the live data show?

a. for some reason, DME does not create Multiplicative type LTFTs of the 1st bank;

b. DME creates the same Offset type LTFTs for both banks;

c. DME does not create normal bank adaptations by temperature segments;

d. DME does not create normal adaptations for Stratified charge;

e. DME works with incorrect Lambda of the banks; adaptation data of all injectors – complete chaos.

The fuel mixture of the banks is incorrect. The fuel mixture of cylinders is so incorrect that half of the cylinders are on the brink of misfire. A COMPLETE crash!

Defective injectors? But they are installed brand new recently!

Live data of the cold start:

No, it turns out that the injectors are not leaking! The average fuel mixture is even lean!

What caused such abnormal behavior of the DME?

And this was the moment when the owner of the vehicle informed me that the software was “upgraded”. Why is it upgraded? Originally, the car was 325i, but the desire is that it drives like 330i. Accordingly, a large, Netherland-based company has performed “chip tuning”. Everything is clear now – this is the cause of the problem.
A next surprise followed very soon. When I informed the owner of the car that, with a high probability, the CO catalytic converters would be destroyed, the owner of the vehicle objected – the catalytic converters were dismantled, and the control probes were disconnected (deprogrammed), too.
No, the control probes are not disconnected! They are warmed up and reporting the data!
But the most epic news “arrived” in the next e-mail – the car still has an inlet manifold without DISA. At that time, I did not even know what to say.
This is an atmospheric engine, and its torque is limited by the amount of air available. If the intake manifold with DISA is not installed, a better cylinder fulfillment with air is not possible. Accordingly – a larger torque (at higher RPMs) is not possible. All gain of the “chip tuning” is precisely ZERO.
What can be done?
The stock software should be restored. All money invested in “chip tuning” – wasted. The owner says that the CO catalytic converters have been thrown away. The cost of new CO catalytic converters is around EUR 7000. No alternatives are available (they simply don’t work). The CO catalytic converters are critically necessary to pass the TI; there are no roundabouts here. Purchase of new injectors – most probably, it was redundant.
This is an excellent example of how to “throw away” more than EUR 10’000. A lot of problems have been gained which now need to be solved.