my girlfriends dads 5.4 is dieing randomly when ideling i got to give it gas to keep it running. now seems like running on half cycl but engine has 15k on it. replaced fuel filter was very dirty and idel air control. only 2 codes are p0171 bank 1 lean and p0174 lean bank2 and misfire number 7

 

Check for vacuum leaks, most common leak is the rubber PCV elbow at the back of the engine. Test the fuel pressure, minimum is 28 psi at idle, normal is around 40.