Question

1999 Land Rover Discovery 4.0L V8 with engine code P1193 (pd) cleaned o2 sensors looked ok lite returned 2 cycles

Answer 1

O2 sensors function by producing voltage when the Oxygen molicules attach themselves to the metal inside the sensor. Replace the sensor and it should resolve the problem. The code is for a slow shift. This means the sensorisn't producing enough voltage for the computer to be satisfied. I would replace the sensor to resolve the problem. The metal inside may be worn so cleaning won't do any good.