help with my oil pressure

[TYL3R hez]

My car's oil psi has been kinda jumpy it will hit 0 psi in 5th gear but it's fine under high load.
It only seems to jump around when at a constant 2k rpm or when down shifting.
Me knowing the sender unit must have something to do with it I order one from napa for $44.00
so today my oil pressure sender unit came in. I replaced the old one and the new one now reads 0 psi...
I ran it down the street and it never left 0, so I got home and put the old one back on there and wah lah its magically working like it was (jumping and figgidy)
What seems to be my problem? Did I just get a crappy opsu from napa or is it something more serious!
I have did the z1 engine flush about 4000 miles ago and replaced the oil today I put in 10w-40 with a bosch filter. If that matters at all.

HELP PLEASE
oh and thanks a million

[Z31toZ32]

buy OEM. Peace!

[TYL3R hez]

think it would fix it????

[Z31toZ32]

mine indicated 0 as soon as the oil heated up and became thinner. i replaced it with an oem and it is back to normal. an alternative is to try drilling out the hole to make it just slightly bigger. i think there is a writeup somewhere on tt.net on doing that.

[TYL3R hez]

i bought a used oem online I will wait for it to arrive and if it does not replace it I will drill one of them to see what happens!!!