2006 Chevy express cargo van 2500 oil pressure sensor

Hello. I have a question. I’ll try to write it once so
you all understand. I have a 2006 Chevy express
cargo van it’s the 2500 model 4.8 8 cylinder. My
problem is similar to most of yours. However there
was someone who said “as long as the ‘check
gauges’ light doesn’t come in” well mine is on. So
when the car is in even when the car is warm. The
oil pressure is at zero. And when I accelerate even
at low speeds it will skyrocket to 80 or max. Then
when I throw it in neutral while driving it will go
back to zero (obviously because I’m not in gear). I
was going to change the oil pressure sensor but I
just want to be prepared in advance Incase that
does work. What do you thjnk is the problem. The
check gauges is on and rhese are my issues. There
is brand new oil in the by the way since two weeks
ago.