I am still searching for my issue.....
Did'nt get a chance to work on my new CCV replacement yet.
But I re-smoked my intake and valve cover - no leaks
assuming you cleaned your MAF? (get MAF cleaner at auto zone).
UPALLNIGHT pointed out this BMW service bulletin, - if your year is 03
http://www.bmwmotorsports.org/pdf/misc/120704.pdf
From my research: (none worked for me)
Many found there issue with the very common rip at the accordion turn of the Throttle Body boot -https://www.fcpeuro.com/products/bmw-air-mass-meter-boot-x5-13541440102
The Idle control valve is dirty
Gas cap not tight
Injector leaky
DISA issues