Get a laptop plugged in, this will tell you all you need to know about sensors being duff or not.

Do you have a wide band lambda and gauge? if you don't GET ONE, it sounds as if the start up enrichment is off, either too lean or too rich with a hot engine. The idle issue to have can be caused by a number of things, I suspect the closed loop idle settings are off. Too much gain will result in a car that hunts for idle, it constantly overshoots its target.

Rob,