Honestly, I don’t think anything is wrong with it. I had an 08 F150 with the 4.2 for 15 years. While the engine is bulletproof, its the slowest thing I’ve ever driven. It’ll get you where you need to go and never let you down, just don’t try to pass anyone along the way.

 

Okay,
Update. I got it to throw a code. It is rich on Bank 1, and rich on bank 2.

 

Yesterday I cleaned the pcv valve and noticed that it fits really loose in the valve cover. Almost to the point of rattling around. Do you think this would cause a rich running condition?