The oil level sensor is atop the upper oil pan on right side. Be sure to replace the gasket if removing. mind the swing-arm. The oil pressure switch is on the left..at or near the oil filter bracket. The wiring harness side connector shells become extremely brittle with age, so be sure to have replacement connector shells on hand if disconnecting....available from Lexus. (Hint..the old ones are so brittle that I simply use small needle nose to break apart the plastic from around the contacts...