p0171 bank one indicated running lean
p0174 bank two indicated running lean
i would look for a vacuum leak first off. the code is telling you that the oxygen sensors are working correct due to it is running lean. look for any vacuum hoses being cracked or torn, then try to see if the intake gasket is leaking. you have a leak somewhere, and since you have both codes its on both banks (both rows of cylinders) could be as simple as the intake tube being loose after the maf sensor.