P0171 BMW - P0174 Code 2001 BMW 325xi station wgn

Question

just had oil change and new air filter installed yesterday, and today the service engine soon light comes on. Is this caused by something that was not install back right.
Thank You

Answer 1

P0171 System too lean bank 1

P0174 Sytem too lean  bank 2

Yes it can,If the air filter was not fitted right and the air duct at the air filter housing is not properly seated you will take in false air and code up a lean condition, so can a oil cap not properly secured will code up a lean condition, and this includes the oil dipstick. Just to let you know to install a air filter on a BMW is not  easy task,the air duct not secured properly.especially at the throttle body.