P0171 NISSAN - Fuel Injection System Too Lean Bank 1
the front o2 sensors are responsible for your a/f ratio, first thing to check here the o2 sensors. did you pull your o2 sensors, they might be caked up or one at the end of its life. check for air/gasket leaks from the maf to the last o2 sensor, ie check your intake tubing, manifolds, gaskets, exhaust for air leaking, its possible there's an unmetered air leak. also a dirty/bad maf could cause this code as well.
the evap canister is behind the left rear wheel, normally you would get an evap code. i would check the o2 and air leaks first. dont forget to check your battery terminals are tight and are getting good voltage motor on&off.