I changed the oil and installed new turbo boost tubes along with a radiator flush. Everything good until next day, I start my truck and walk away while it warms up. I come back in 15min. get in and notice low oil pressure light on, gauge reading zero. Everything sounds good, oil is good. Could it be just a sensor or is it the oil pump, how can I tell?

 

Why do you "let it warm up for 15 mins" Great way to sludge up the crankcase and waste fuel.
I doubt you will find that as an authorized procedure in the operator's manual.
Look for a wiring harness issue for the oil light/gauge. Start checking the easy to access stuff first.
Regards,
Eric