Hesitatation/intake back fire/no codes

[hampsterzone]

Please help! I have changed my spark plugs, spring caps, coil packs, cam sensors. My engine hesitatates, jerks, and back fires up front (intake area). Only when I am under load trying to accelerate. When cruising this is not observed. No codes are thrown except system too lean on bank #1 sometimes. This is crazy, no one really knows what is up. My mechanic couldn't get a misfire history or any codes. Ford said it could be the wrong plugs as they have seen that before from Auto Zone. But it ran fine for a month before. I changed the coil packs to see if that was it. And the cam sensors because it was cheap and easy. Still the same thing happening. Ford also said it could be a plugged converter. Has anyone experienced this kind of trouble? I was told it could be a dirty mass air flow.sensor too. Possibly the VCT Solenoids? Any help would be appreciated. Could Bill or Cody respond. I am in serious trouble if my truck breaks down, as I use it for my job all the time. Thank you!