Why does my car stall while driving?

To tell you the truth it sounds like a faulty alternater. If this is the case it would do evrything you have jus discribed. The reason being is i've had that same problem and took it to advanced auto and they said there was nothing wrong with it and that evrthing seems in check. But this seemed to be entirly incorrect bc a alternater can be at break point and pass a test but it will eventualy just stop. Which is wat sounds like is happening to you. So my advice to you is to gey ur alternater replaced and if it still happens which it shouldnt but if it does its a vacum leak. Hope this helps