The shutting down while driving issue could be the ignition switch. It's $100 part that controls all of the functions of the car. It typically causes the engine to crank and not start also. I had the same problem with my 2001 4.4. I cleaned the switch with contact cleaner and it got better for a little while. I still wound up replacing it.

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2007 Suzuki Vinson 500 4X4
2007 Toro 6.5hp
2006 BMW X5 4.4 ltr (his)
2001 BMW X5 4.4 ltr (hers)
1994 Honda XR650L
1984 Honda XR80

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Benjamin Franklin