Hello and I know some of this has already been covered but I really need some advice.

A little history on the truck. I'm the second owner of the truck. My father left it to me when he passed. He purchased it new.

Its a 2002 f-150 super crew. 4.6 v6 with 77,000 miles. For the last year I'm getting lean codes on bank one and two. Too address the problem so far I've.... new mass airflow sensor, new EGR valve and tube, new plugs, wires, coil pack and a new fuel filter. Also had the intake system cleaned out at the shop. When they inspected they intake system I was told all hoses O rings looked good. After each fix the truck would run great for about a week then the check engine light will come back on and I'm getting lean codes again. where do I go next?

Second question.

This Truck has a lot more sentimental value than monitery value. With that being said... In addition to the above work I've also replaced the following in the last year...

tires, exhaust, all ball joints, tie rods, complete front breaks including calipers, every single break line, engine belt and all related components, air filter, power steering high pressure lines, climate control module.

So as you can see I've put a decent amount of money into the truck. As far as cosmetics the truck is very clean inside and out, with the exception of some minor rust on the tail gate. At what time do I cut my losses? Any input will be helpful.

 

Check the PCV elbow on the back of the throttle body. Inspect the line as well, all the way to the PCV valve itself.

BTW, your motor is a V8 rather than a V6.

 

lean codes on both sides is a vacuum leak.
Check (and maybe just go ahead and replace) all vacuum lines.
The PCV elbow is another common failure, since it may look fine when taken off. That can be replaced as well (as well as using only a Motorcraft PCV).