Update:
We are getting closer.
Today, I got a
new VDO/Continental MAF installed. I immediately saw an increase in the new MAF signal vs. the Chinese MAF vs. My original BMW "old' MAF. Now, the MAF shows
~4 g/s at idle vs 2.x-3.x before. Considerable difference. As expected, car feels more dynamic.
Yesterday I had some downtime and I was waiting for the new purge valve anyway, so I cleaned the existing purge valve to see if it would make a difference. I didn't see a big difference.
I still have an issue with STFT, which now has been mostly negative. At load, the STFT becomes closer to normal. You can see the STFT trend up/down at idle times. During idle, the STFT is definitely negative (running rich). I am hoping this is due to the purge valve (new one should be here sometime today) getting stuck open and/or not closing appropriately. Or maybe the car just needs to learn things and will adjust to the correct numbers over some time. After the MAF replacement, I still see the biggest improvement.
