Intermittent miss I can't find
 

It's a 2002 Hyundai accent, my teenage daughter's car.
It will occasionally stall when idling.
It will sometimes drop a cylinder whilst driving. Not for long, just a few seconds.
Reving the engine gets rid of the miss.
It shows no codes or problems.
I replaced the crank angle sensor.
The plugs & leads are good. It doesn't miss under load.
I disconnected every sensor connector I could find, all looked good.
I wanted to disconnect the ECU to check the connection but wasn't sure how the connector releases.
Any ideas anyone?

My first guess could be a bad catalytic converter that is getting clogged, possibly bad oxygen sensors as well. I would either have a mechanic check it out or use a product like Mr. Gasket Cataclean if I knew that the Cat was the problem. It sounds like your car is not ventilating exhaust fumes at low RPMs because the outward pressure is not high enough to completely ventilate, and once you press the gas the pressure increases allowing the exhaust to flow out.