P0171 code only need help!!!

[Joshua Ballard]

I have a 99 expedition 5.4 eddie bower 4x4 and i can not figure out this lean condition on bank one ive replaced pcv because of oil in the throttle body the fuel injectors i got good fuel pressure i ran a smoke test and found smoke coming out of the cap of the IAC so i replaced that and i checked the fuel pump and lines for the hell of it and even replaced the fuel filter and there was alot of pressure on feed line but return line was completey dry it idols around 7 hundered RPM the misfire gets really bad around 1500 RPM but gets better at higher RPM but still has a pretty solid misfire ive erased the code a couple times and P0171 is the only code that comes back up and all the system checks comes back ok except cats and evap says INC incomplete oh and it has 209,000 on it ready to give up really need help

 

[Joshua Ballard]

Im about to replace evap on fire wall and the square box with 2 hoses on it and the cylinder bedide it on the vaccum system will give update if any of that fixes the problem

 

[craig sargood]

Hey, I don’t know if you’ve googled the code or not, try watching a few videos to point you in the right direction before you just replace a bunch of parts. There’s quite a few videos. Hope this helps

 

[Plati]

https://www.expeditionforum.com/threads/obdii-reader.34543/#post-288245