Malibu M6DI/LT4 Post-Cat (Downstream) O2 SensorPost Catalytic Converter Oxygen Sensor (Post Cat O2 Sensor) Location: Mounted in the exhaust elbow system or exhaust y pipe after the catalytic converter Installation Tips: Safety First: Make sure the engine and exhaust are completely cool to avoid burns. Disconnect the battery to avoid electrical shorts. Locate the Sensor: Find the post cat sensorit's the one after the catalytic converter in the exhaust pipe. Trace the wiring harness to confirm