Cuts out when driving. Turn ignition off and on and will restart and drive.

No other symptoms were noted. Have to drive for almost half an hour before the problem occurs. The vehicle performs well under a variety of conditions. There is a turbo timer installed but has been temporarily disabled. The problem has been present for about 3 months. The customer has replaced the EGR valve and fuel rail pressure sensor subsequent to the onset of the problem in an attempt to fix it themselves.