Oil pressure goes up and down
Possible your pump is starting to go, or some debris in the engine. I'm not a fan of power flushing a car but I think you should have it done, its cheaper then replacing the oil pump.
it could also be a sending unit how is the oil level . how many miles do you have on it and is it new oil? dose the motor rattle or make noise when it goes down
CHECK WIRING ON THE UNIT
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