My '03 would have that "jerk" occassionaly while cruising on the highway in OD when I first got it last summer with 57K on the clock. Not sure which one of these fixed it, but it doesn't do it anymore. In fact I forgot about it until I read this post..I've changed..
Fuel FIlter, plugs, wires, cleaned MAF, TB, PCV valve, etc (all motorcraft parts). I did notice that it would have a barely noticeable stumble sometimes at idle before I swapped out the plug wires. They looked to be in great shape but after 8 years I'm sure they needed replaced. Everything seems tip top now. I found that O'Reilly autoparts down the street sells actual Motorcraft parts now so that makes it easier to find on a weekend if the the dealer is closed.
Now has almost 61K miles.
'03 XLT/FX4 L1 4x4 4.0 Arizona Beige Automatic (my weekend ride). '16 Ford Escape Titanium ecoboost (wifes ride) '16 Ford Escape S (my work ride)