Spark plug would show as a misfire- not lean bank 1

Could be injector problem, vacuum leak (most likely), MAF sensor, O2 sensor.

Do you have a scan tool that shows data?

__________________
Dave

'05 325xi
'10 E70 35d
'85 911 Carrera
'66 911 Work in progress
'91 Chevy C1500
'95 Jeep Cherokee
‘18 Jeep JLU