RomRaider

Hi,

I have a 523i M52 and trying to diagnose a rich condition on bank 1. I hope someone can give me a direction to where to look next, I think I tried the most obvious components already.
The engine idles ON bank 1 has big negative values (it can GO TO -40) When that happens you feel a little roughness in the idle.
When we rev it up TO above 4k RPM the STFT will rise again till the point you idle again, then it drops back to mostly around -20

I do have some roughness on cylinder 3 and , but don't know if that has to do with this low STFT on that bank, I suspect it does.
What I did till now:

- changed MAF (I know tats not bank related)
- changed plugs and coils on bank
- changed injector only on cylinder 3
- Did a total vacuum check underneath the intake and replaced the CCV (I know its not a lean condition)
- Changed o2 sensors
- changed cat
- changed fpr (I know thats not bank related)

I am wondering what I can do more to determine what is causing this condition. Besides this the car starts and runs great with a good idle (little rough when its too low in adaptions) It just that I want to try to know it technically (hobby) I hope someone can give me some extra directions. My guess its an internal leakage what do you guys think? I can imagine that when cylinder 3 has internal leakage it will be rough on INPA and is playing with the fueltrims. I think I checked all the external components that are bank related, but I need to be sure.
Again, the car is very usable and for a 523i it runs quiet well, its the technical part I am interested in.

I will upload some photos and videos in the hope someone sees something.
There is one error in INPA that is bank 1 related and keeps coming, I know that is related to my issue. (see photo)

In the next video you see INPA adaptions

https://www.blackshalo.com/inpa-adaption.mp4

In the next video you see INPA roughness

https://www.blackshalo.com/inpa-roughness.mp4

And I recorded a csv file



I have an extra question about lambda's on these vehicles. Is it normal that when you let loose of the gas you have fueltrims flatliners? On both banks I see when I full decelerate both banks go zero. I thought that the lambdas must always swing and nothing more. When you look at the INPA adaption video you also see that bank 1 lambda is not as swinging as bank 2.
Maybe this is normal behavior but I noticed it and I am wondering.

fuel cut off happens on decel. therefore lambdas flatline

i would reverify with anther known good lambda sensor. maybe faulty out of the box or you bought aftermarket junk