Check engine light came on in my wifes Sentra. Got codes scanned at Advance Auto and they came back P0171 System too Lean (Bank 1) and P0174 System too Lean (Bank 2) and pending code P0171 System too Lean (Bank 1). What would be the cause of this and how do I fix it? We have had the car not even a week and the light came on after I fueled it. Is this something I can fix or should I take it back to the dealer and get it fixed under the warrenty? Thanks for any help.