Well if the engine lost power and slowed down, the oil pressure would drop.
As to why it lost power, fuel pump maybe. Cat converter going bad.
97 Sahara, 74 Renegade, 72 CJ5, 55 Willy's (the Beast) Boss 302, 6:34 gearing, Bose 901 speakers.
God I miss that Jeep. Forgot the kinda Jeep, 80 SX4.