Help! Can't figure out lean codes.

[Dune Runner]

Ok 99 4.0 OHV. So far this truck has had the fuel pump, MAF, TPS, Intake gaskets, two O2 sensors, Injector O rings, replaced.
Two independent shops and the dealer have gone through the truck. The PCM has been reprogrammed with updates. It has been checked for vacuum leaks many times. I even checked myself. I reset the ECU and within two days the CEL is back on.
Im stumped. The truck runs great and otherwise has no problems running ,starting , idling or driving.
Any ideas? It's been smogged and won't be due again for two years so it's not a pressing issue but Im anal about things and it bugs the crap out of me not knowing what's wrong. BTW this truck came stock with no EGR system. The codes are lean bank 1&2.

 

[adsm08]

Do you have access to a scanner that will do live data?

I have a few good tests to give you but I need you to have a scanner that does live data.

Not saying this is your problem, but I have seen lean codes caused by failing injectors without any other driveability symptoms.

 

[Dune Runner]

No scanner but the Ford dealer had one on it. They had it all day and were stumped too.

 

[Dune Runner]

Im hoping you guys might have more ideas on it. I have been spending all my free time trying to figure it out.
Things I have thought of but haven't checked yet like a bad gas cap, Bad connection somewhere, EVAP purge valve leaking, Stuck PCV, Leaking dip stick, You know the stupid stuff. I have to write them down as I think of them so I can check them the next day.

 

[john93rangerstx]

craked intake when it cold it shrinks and leaks i have seen people silicon a crack they made and it come bake weeks later

 

[Dune Runner]

craked intake when it cold it shrinks and leaks i have seen people silicon a crack they made and it come bake weeks later

Nope, The intake has been off the truck and inspected.

 

[gator1gear]

I have a 2000 Ranger 4x4. I drove myself crazy trying to find the cause of my lean code. I changed the fuel filter and cured it. I know it sounds strange, but it fixed mine.

 

[Dune Runner]

It has a new filter and pump. Im replacing the filler hoses in the AM

 

[gator1gear]

It has a new filter and pump. Im replacing the filler hoses in the AM

I hope ya get it! I imagine it's pretty frustrating Good luck!

 

[Tominator]

Clean the MAF.....

 

[Dune Runner]

Clean the MAF.....

The MAF is new and clean.

 

[adsm08]

No scanner but the Ford dealer had one on it. They had it all day and were stumped too.

They aren't trying hard enough. Must be Mexican'ts since you are in California.

I bet I could figure it out with the truck here.

 

[Dune Runner]

They aren't trying hard enough. Must be Mexican'ts since you are in California.

I bet I could figure it out with the truck here.

At this point in time I wish I were closer. I did replace the fuel fill hoses today and found the line from the purge valve? off. The one on the back of the tank. Nothing seemed wrong with it and I just pushed it back on till it snapped. The fill hoses were trash. They fell apart in my hands.

 

[Tominator]

Sounds as if you found the prob...

 

[Dune Runner]

Sounds as if you found the prob...

I can only hope. I have found so many things wrong with this truck it's unreal. It only has 124k on it. I think the previous owner had his head up his arse.
I will know in a few days for sure.