Hi knowledgeable ones
I think my SRT has the old HE Pump fault

the car has covered 45,000 miles and so i guess it's in that zone.
The way the fault manifests is that one minute you got accelerate and all is well and a you try again a few minutes later and there is nothing their, repeat the process a bit later and the power is back again.
My question is how can I be sure it's the Pump and not a sensor or something? Are there any checks I can do to confirm my theory?
TIA