Intermittent Miss in a 2001 Duratec

No codes show even when monitoring. Intermittent miss that shakes the car. Goes like a rabbit, so I dobt that there is a fuel problem. Fuel economy has not dropped. Only notice the miss at idle or very slow speed. Already: New Plugs (Good Compression) air and fuel filters.
Although I doubt the fuel system, I'm going to check fuel pressure and monitor. What should the reading be?
The shake is sometimes so great that it almost sounds like the spark is way too early. What triggers the coil pack? Could that sensor be defective? The problem is not temperature related, as the problem occures in both a hot engine and upon startup.

Any guidance would be appreciated.

My 2001 has started doing something similar.

Same thing, still 30 MPG, still runs great, but at slow speeds usually starting from a stop, the car shudders once in a while. I noticed however that when this happens to me, the traction control light (little green tire with water spashing off of it) comes on and off quickly, so it's not the engine missing, it's the traction control kicking in (feels more like it's pulsing a brake caliper). Try to pay attention when it appens again and see if that's it. My fis is to turn off the trac control when I start the car. :)