I have a 2006 F-150 with the 5.4L. It has 82,000 on it. I had the plugs replaced at the dealership. None broke thank GOD. Ford only made $307.00 off of me. I have also replaced the fuel filter. I am still having a slight hesitation when accelerating at low speeds. It is not showing any codes. My cousin said that his 2004 was doing the same thing, so he took it back to the dealership. They said they had to adjust some settings in the computer. It got better,but his still hesitates from time to time. Mine is not bad, but is noticeable. Could it be my computer or do I look for something else first. My uncle thought it might be the sock filter on the fuel pump that may be clogged. Has anyone had this problem?

 

ALOT of the 5.4's do it. Mine did it until I put an engine tuner on it. Made a world of difference. I found a used tuner for $200 and it works awesome.
I have an 05 with the 5.4