BMW codes P0171 & P0174- what do they mean?

Question

Just purchased used car & light came on before I got home. Had it a analyzed and these codes popped up

Answer 1

P0171 Fuel trim lean Bank 1

P0174 Fuel trim lean Bank 2

P0171 and P0174  and fuel trim code condition , when there is a lean fuel trim there is more air than fuel ratio, False air are the most common cause for a lean fuel trim on both side of the Bank this would be missing or not secure oil fill cap, missing or not properly secured oil dip stick or even the PCV system.