This time – an example of the typical technical condition of the NOx system of the N43/N53 series engines.
E series N43/N53 engines (and the exhaust of the cars) are at least 10 years old now. N53 of the F series are a little younger, but their exhausts are not in better condition. The reasons are simple: MSD87 hides problems with the exhaust (records the error messages very reluctantly) and – “survives” the issues of the NOx systems slightly better. Accordingly, the users are not motivated to solve the problems, and the exhaust is damaged much more, much more roughly than for older vehicles.
When I claim that today, in the Year 2022, unfortunately, 99.9% of NOx catalytic converters have lost their performance, many don’t believe me. There are still optimists who hope that the NOx catalytic converter of their car is still “alive”. Here is one example.
I got a message from one user of the N43 series engine:
Engine Type: N43
A little rundown of some issues:
I have just now in February changed the NOX sensor at 145270km, and it is starting to make trouble again, it seems like the NOX value keeps rising at an abnormally high pace. Since the NOX sensor got replaced, I must have done 2-3 Desulfatisiering phases. Is it possible that the BMW workshop missed something when installing the new sensor? Or is it something else that you can see that does not seem right?
So, since the installation of the NOx catalytic converter (2 months ago), the user has driven 4500 km, performed 2 .. 3 desulfation sessions, now the error message 30EA is recorded in the error message memory (too significant contamination of the NOx catalytic converter), Stratified charge – turned off. It turns out that the desulfation sessions were performed not less than after each 1000 km, and still they have resulted in too high contamination!
Let’s check all data initially.
Yes, the odometer readings correspond to the readings submitted.
Here is the data from the NOx sensor. All data: Lambda linear; Lambda binary; NOx content; Offset – is correct. An excellent sensor! The car owner hasn’t spared money on a new OEM sensor!
At the same time:
As we see, the status of the error message: active. The error message is recorded at the moment when the contamination, calculated by the NOx sensor, has reached 490mg.
And even the History memory is full of 30EA error messages:
And finally, let’s see the actual contamination of the NOx catalytic converter:
Yes, everything corresponds – the existing contamination is very similar to 30EA freeze-frame data. All data submitted by the user are correct!
What do all these data mean?
The contamination of the NOx catalytic converter grows with a speed of 0.5 mg/km. It means that from 0 till 490 mg (when the 30EA error message is recorded), 950 km are driven. Unfortunately, it will take a considerable effort to clean the NOx catalytic converter to 0. By such profile of the NOx catalytic converter, you will manage to “delete” 60 .. 70%, not more (remember – you have to drive evenly with a speed of 110+ km/h). This means – the exact car has required desulfation after each 550 .. 600 km or even more often if the user has no option to drive for more than half an hour with increased speed. The user could not perform the desulfation sessions so often, so the error message 30EA has been recorded regularly.
It is clear that such often desulfation sessions and continuous recording of the error message 30EA is a nightmare!
You have to remember that the 30EA means – DME turns off Stratified charge; the consequences are precise of the same importance as if of any other damage to the NOx system. Even more – this is the fast road to the error message 30E9. 30E9 means: DME has confirmed the reduced performance of the NOx converter (not taking into account the performed desulfation sessions), and a Stratified charge is turned off for all. In this case, only replacing the NOx catalytic converter will help. Or… NOXEM.
Let’s make a short comparison of this situation with NOXEM.
In addition, the larger the allowed contamination of the NOx catalytic converter (“better” profile of the NOX catalytic converter), the faster and easier the desulfation sessions are done. This feature is included in the DME algorithms. It is logical – if the catalytic converter is perfect (even considerable contamination indicates good performance), why torment the user switch long desulfation sessions! In the case of NOXEM, it is enough with a desulfation session of 15.. 20 minutes by the contamination of 3000 mg to “delete” at least 2000 mg! NOXEM allows the contamination of the NOx catalytic converter even till 3000 .. 3500 mg, which means – the interval between complete desulfation systems is at least 6000 .. 7000 km.
In constant, in the case of the exact OEM system: a desulfation session has to be performed after each 550 .. 600 km; the required length is longer (at least 30 .. 40 minutes), several hundred mg of the contamination are deleted, and even in such conditions the 30EA error message is recorded regularly.
Finally – if the NOXEM is installed, the existing desulfation systems are not to be performed at all; you can delete the contamination of the NOx catalytic converter at any time you want, using ISTA.
This time the only thing I could suggest to the customer: is either install a new NOx catalytic converter (costs of at least EUR 2000) or install NOXEM. Unfortunately, EUR 500 recently invested in a new OEM NOx sensor, are used quite useless. The only benefit – we got a 100% confirmation that the NOx catalytic converter is worn out.