5.4L 2v Intake Manifold Gaskets P0171 P0174
 

Now this a more complicated job so hopefully this video will help those who would not have attempted this big of a job otherwise. Lean codes on these 5.4l and the 4.6l are very common as the intake gaskets compress over the years. This was done on a 2001 F150 5.4L 2v other years of this generation are only slightly different. I hope this helps.