[zEDo]

Hi everyone,

I'm getting a rather high gas mileage in the city (14-15L/100km in city, out of the city it's normal 6-7L/100km) on my 200tkm 2011 320i. Did coils and plugs, coils were pretty black but dry and all of them were the same so I don't think that's a big issue, just normal carbon from DI engine. Then I tried checking if my stratified charge is working properly, it sort of is. I did a couple desulphation sessions, the cat did clear up pretty nicely, although it does seem to clog up a bit faster than normal, might be normal at this mileage.

Anyway, using inpa I managed to track down some lambda readings that are a bit off (post-cat probe reading more oxygen than the pre-cat probe)and led me to think I might have an exhaust leak. Went to the shop and sure enough I have a leak in the flex pipe, I'll get it replaced this week.
In the mean time I found out that 2 of the Injector adaptations are not learned by the ECU and one additional one that shouldn't be, is. Does anyone know exactly what each adaptation does? What could it mean? Google translate helped a bit but not much.

Blue should be learned, red should not be learned, according to bimmerprofs.

Sorry for the long post, any help is much appreciated .

[zEDo]

I'm back with a couple of updates:
1. After replacing the flex pipes in the exhaust, the cars feels as if it gained a bit of power in low load and low rpm. The throttle response is also a bit sharper.
2. The missing adaptations were not learned and the gas mileage is still pretty much the same. This made me dig around in inpa for hours trying to figure out what was wrong and I think I found the culprit: The post-cat Lambda sensor, the narrow-band one. I think it's faulty or at the very least aged because I checked its internal resistance right after engine start and it's out of spec, around 16kOhms for the first ~10 minutes of idle, then it drops to 768Ohms, then 512 and after around 20 minutes it drops to 256 Ohms.
According to bimmerprofs the probe should be warmed up immediately after start-up by the ECU, 1 minute max for its internal resistance to drop within spec(512 Ohm max).
The pre-cat wideband probes are fine from what I can tell, at least they warm up properly.

So I think what's happening is the narrowband probe being faulty/old is feeding wrong data to the ecu which uses that data to calibrate the wideband probes, which are used to calibrate, in turn, the injector adaptations. It's sort of a domino effect. That's why I'm planning on replacing the narrow-band probe, performing a desulphurization session, deleting all injector adaptations and then I'm hoping it will relearn everything properly.

Below you can see the lambda readings after 10 minutes of idle/warmup.

Any advice on the matter is much appreciated! Cheers!

[zEDo]

Back again with another bunch of updates:

I replaced the narrow-band probe with a new one. After about 200km of driving with it, the only thing I noticed is that one Lernbit was learned, however I think it's just a coincidence because it was learned right after I installed the new sensor and seeing how these adaptations are learned over time, it most likely happened with the old probe.

Today I decided to perform a desulphation session, delete the old adaptations and re-learn new ones.
I ran the re-learning procedure mentioned on bimmerprofs and all of the adaptations have been re-learned APART from the last one. So I'm stuck in the same rut.
I'll update you on the lernbits after a couple more hundreds of kms.

Anybody had a similar issue with that pesky last lernbit?

Cheers