Is SES flashing? Do you have any hard data from the ECM or just a code?

Could be a bunch of things:

MAF
fuel pump
bad gas
clogged injector
vacuum leak
bad o2
etc.

BTW, check the vacuum hoses at the rear of the engine. Did the shop fool with anything else under hood while you were getting the codes scanned?

__________________
Dave

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