P0301, P0171 what is next?

[ProjectAviator]

I have a problem with my 2000 Limited 4.0 it is running rough. Throwing P0301 & P0171. I have since replaced the intake gaskets upper and lower (twice) MAF, New plugs in 1,4,5,6. New wires in 4.5.6 new coil. and New PCV. With the weather I haven't gotten to the 2. 3 plugs and 1,2,3 wires. with those parts being replaced. What else can it be?

Thanks
Tim

 

[1991 sploder]

Vaccum lines / vacuum to fuel pressure regulator...

 

[TribeZ]

I had a 0171. And cleared it after replace the hose from the intake manifold running under driver side tire to the evap system solenoid. I also tapped the solenoid a bit looks like a little horn or something underneath the battery above the wheel well trim. Could also be any other part of your evap system. Tubbing from exhaust manifold to egr, tubing from bumper area back to the gas tank etc.

 

[RickOTR]

How many miles on your truck? Might be a fuel injector sticking or leaking down.

 

[ProjectAviator]

She at about 168K

 

[RickOTR]

Time to start looking at fuel injectors for sure. A temporary solution is to put half a bottle of Marvel Mystery Oil in half a tank of gas then drive it around town or the highway keeping the rpm's about 3000 to 3500 for a few days. This will help dislodge any carbon in the injectors. However, it's time to start looking at new ones as Ford recommends replacement around 100k miles.