diagnostic code on 2004 Ford F-150

The engine light came on my dash, took it to auto zone to have them do a quick check and they came up with the diagnostic code P0174, can you tell me what this is and is the repair costly? I just bought this used truck 2 months ago and now this....Thank you for your help!I think it has to do with the oxygen censor????

Asked by for the 2004 Ford F-150
the fault is bank 2 running lean. check for cracked vacuum hoses or any place air can enter the intake.
1 more answer
do u have a P0171 also or pending P0171 ,if not its prob not a vac hose cause vac hoses will cause both banks to read lean id go with wiring to O2 sensor or sensor itself