When was the last time you changed plugs, plug wires, cap, rotor?

Does it do it more/less in wey/dry weather?

How does your wiring harness look in the engine bay?

My thoughts are, it sounds electrical in nature but, that covers ALOT.

Checked your pressure relief valve on the fuel rail?

Got a cold-start injector? Is it leaking?

I have had all these problems and most all exhibited your described symptoms.

You might try spraying a little water on the plug wires while idling to see if the car dies indicating bad plug wires. Check the cap for carbon tracking and the rotor for burned spots. Could have a coil going bad, tap on it with a piece of wood or a rubber mallet and see if the engine misses. Could be CPU problems. Could even be a faulty ignition switch. Sounds as if the air-bypass might also be giving trouble (idling problems) or the throttle position switch is bad.

Does it seem to miss on all cylinders or just one or two?

Could be a bad injector or loose connections to the injectors.

I have given you a LONG afternoon of stuff to check and even with this list, I am sure there are things I forgot to mention.

Good luck.