Alex,
I have some codes I cannot clear in the DME module's shadow memory too. I scanned my car with another tool call Win-Star from Taiwan and cannot see those codes.
So I think , those in Shadow memory are somehow old codes cleared earlier like most electornics design the code is marked deleted/cleared but not actually cleared from the memory location until it is overwritten when the memory is full/recycled.
But why some can be cleared ? perhaps less critical codes can be permanently cleared. A lot more to explore.
I think we should try to get very one to post the screenshot of the DME live data at idle, by comparing the data (air/oil temp, air mass, o2 , vanos position, etc) will give everyone a better understanding of condition of their rides.
Jarance, I notice your oil temp is quite high compared to mind at idle .
E46 325 M54 MS45 EWS3