93 civic with the z6, I get cel 22, which I know is the vtec oil pressure switch/sensor.

Heres the kicker, it passes all the tests that the Haynes manuel says to check, and vtec works for the first say 10 minutes of driving but after that it cuts out and then throws that code.

I'm confused, do I need the whole switch or is there something simplier then that that could fix this issue?