Removal

1 The knock sensor of Fiat Punto is screwed into the rear face of the cylinder block, behind the alternator rear mounting bracket.
2 Firmly apply the handbrake, then jack up the front of the car and support it securely on axle stands.
3 Trace the wiring back from the sensor to its wiring connector, and disconnect it from the main loom.
4 From under the car, disconnect the knock sensor wiring connector.
5 Undo the sensor securing bolt and remove the sensor from the cylinder block.

Refitting

6 Refitting is a reversal of the removal procedure, ensuring that the Fiat Punto sensor securing bolt is tightened to the specified torque.