1999 S80 2.9 non Turbo Low Oil Pressure - Stop engine

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After a long drive with AC ON when I stop the car I feel like RPM Start fluctuating between 500 to 1500 and shows the error "Low Oil Pressure - Stop engine" and stops the engine. Mostly it happens after I use car running with AC...without AC it rarely comes.

As per my research either the Oil Pressure sensor is culprit or Oil Pan seals need to be change.

Will appreciate any other experiences of you guys tried.