BMW fuel system and air intake diagnostic guides — fuel trim analysis, MAF sensor, vacuum leak detection, and turbo boost problems.
Short-term vs long-term fuel trim thresholds, bank balance test, lean/rich cause tables.
Fuel TrimSTFTMAF deviation rules, g/s reference values, cleaning vs replacement guide.
MAFP010110 common leak locations, smoke test process, load vs throttle correlation.
Vacuum LeakBoost vs throttle correlation, P0299 underboost, N54/N55/N20/B58 turbo table.
TurboBoost