SRT8 randomly shutting down

While driving my friends vehicle under forty, it will randomly shut off. The harness has been ohm, 2 PCM's replaced a TCM, cam, crank, map, TPS, throttle body, o2, and pretty much every other sensor you can think of has been replaced. I want to check the fuel pump for intermittent operation but my buddy is (absolutely) sure that is not the problem. I want to ask simply because now he is looking to replace the front control module and entire wiring harness which we all know is mind blowing expensive, especially if it does not fix the problem. Can anyone help me? Oh and it was at a certified mechanics shop for five months.