In this entry – one of the examples for 30DE error message 

Let’s see closer the attributes of the error message.

Lambda-istwert for both banks is 1.99, which means – the engine has worked in Stratified charge mode with Lambda around 2. This mode is also confirmed by Zustand Lambdaregulung: mode 3 – Stratified charge.

In this mode – 200 mV: NOXEM indication is correct.

Instead, Lineares Spannugsignal 3.27V means Lambda indication >10. Increased Lambda value means probe, poisoned with fuel. Here, you will find more exact information, case No.3.

Good news: NOXEM live data indicate that at the moment of data gathering, the NOXEM is working correctly: 

Here, Lambda 3.28: also Offset value in Override mode is confirmed and correct.

For the control, we make sure that the engine really works in Stratified charge:

Exactly – the engine works in Stratified charge! Everything is fine – all Lambda probes indicate a similar fuel mixture!

All other live data for the warm engine – correct. The owner of the car has no claims regarding the performance of the warm engine. The cold engine experience is completely different – permanent vibration can be felt. 

Here, the video screenshot from the cold start of the engine. We see that:

a. the fuel mixture in both banks is rich (Lambda voltage <2.00V);

b. mechanical efficiency of cylinder No.4 (by firing order) is strongly increased – its injector is strongly leaking;

c. the efficiency of cylinders No.3 and No.5 also is increased – the injectors are dripping in the closed position.

Further work will be the replacement of the leaking injectors. After replacement – don’t forget to perform the re-adaptation of the engine. 

Yes, in this case, the NOXEM continued to work correctly after the replacement of the injectors – its probe “got well”. Unfortunately, if the repair is postponed, the probe can get so strong poisoning that the only solution will be to replace it. So – don’t postpone the repairs! NOXEM (and also the OEM NOx probe) are not the only ones, which can be damaged by leaking injectors! The same can happen to other Lambda probes and also to the expensive CO and NOx catalytic converters!