[94talonawd]

Do you have a pocket logger? I would use that to check your isc. You can tell if your isc is working by looking at the steps displayed by the pocket logger.

Im not saying that it is the ISC, but it is worth looking into it.

And you also make it sound as if the bov is vented into the atmosphere.
You're describing it just like how a vented bov would do to a car, but then you also stated that your car is all stock. Definitly check for any boost looks, and check your BOV recirculation fitting. Also check your base timing, and base idle properly.

Also, and to just keep in mind, some 3/s have problems with their ECU capacitors that would somewhat cause this kind of symptom, and this involves replacing the ECU itself, or replace the capacitors.

I would also try swapping parts in and out to see if that is the problem.