Most likely the Engine Computer has to relearn what Chrysler calls "minimum throttle". With Chryslers, you drive at highway speed with the engine warmed up, then coast for at least seven seconds without touching the pedals. Your car will likely have a similar requirement. Usually whatever that requirement is, it will occur with normal driving. Your fuel trim numbers will also be lost from memory so the engine will not get the right fuel / air mixture until that is relearned. That also is done by driving it.