BA xr6t ongoing running issue

[ERICtheBERIC]

Ive been having an intermittent issue with my BA xr6t manual that's absolutely doing my head in.

 

While driving at constant speed, the revs will suddenly drop all the way down to idle while my foot is still on the throttle. It will then idle rough and when I reapply the throttle it will stall out completely. When I go to start the car again, it does not crank and the battery light comes on the dash. After turning the key all the way back and trying again it will eventually crank over and run fine for some time before going back to the issues described above. Seems to only do it when its warm and it logs no faults on my torque pro app.

 

Parts I have thrown at it to fix the issue so far:

crank angle sensor

throttle position sensor

new plugs and coils

new battery

new fuel pump and filter

 

Ive bought a second hand throttle body to try but I dont have high hopes that that will fix it. Any other ideas on what else it might be fellas? Im really at a loss here, any input would be greatly appreciated.