To further expound. I use the Torque Pro app for reading codes. When my CEL first came on I checked and it showed P0174 as an Active fault and P0171 as a Historic fault. I disregarded the P0171 fault, not knowing why it'd show as Historic. After cleaning my MAF, replacing the bank 2 air fuel ratio sensor and even replacing my gas cap the CEL kept coming back on.
Had a buddy user his code scanner last week and his scanner showed P1071 as a pending fault with P0174 as active. Finally took it into a shop to get diagnosed. The result was that the fuel pump was going bad and couldn't maintain proper PSI. Seems early for a bad fuel pump, but I had them replace it regardless.