Hi all, I'm getting really fed up in finding the root cause of my 2012 F10 N20 supposedly running lean. I hope there's someone with an automotive major reads this and able to advise me.
I was able to read my STFT and LTFT using a bluetooth ODB scanner connected to my phone.
Findings:
I have a varying SFTF readings (Sometimes +10+% and sometimes -10+)
I have a consistently high LTFT in the +20+% which so high that my fuel consumption increased a lot and only getting about 320KM on a full tank in the city
10.0.0.0.1.
It gets weird....
When I increase the rev, sometimes LTFT goes down (Signs of vacuum leak)
When I increase the rev, sometimes LTFT goes up (Signs of fuel delivery issue)
I can't get around the fact why it's not consistent. Can I have both issue present?
I have brought it to few shops, no one detected any vacuum leak
Parts replaced:
4 new coils and plugs
New HPFP and 4 new injectors
New oxygen sensors (Both down and upstream sensor)
New MAF sensor
A lot of $$$ gone down the drain and none fixes the issue.