The symptoms you described are similiar to what my car was doing except it had never stalled on the highway. What I noticed was prior to the car stalling at low speeds or idle, the temp. sensor gauge in the car would start acting eratically, or drop to a reading of 0. If I was on the highway, I ...

Not sure if this will help...but I have a 94 850 and I too had stalling problems recently. It started stalling once in a while, probably every couple months, and usually when I would decelerate at a stop sign. I thought nothing of it until my car began stalling more often. During this time, I also ...