Heated Exhaust Gas Oxygen (HEGO) sensor - removal and refitting

Note: A new sealing ring will be required on refitting.

Removal
1 Apply the handbrake, then jack up the front of the vehicle and support it on axle stands (see “Jacking and Vehicle Support”).

2 Disconnect the battery negative lead.

3 Unclip the wiring and disconnect the sensor wiring plug (see illustration).

17.3 Heated exhaust gas oxygen (HEGO) sensor - 1.4 CFI engine
17.3 Heated exhaust gas oxygen (HEGO) sensor - 1.4 CFI engine

A Sealing ring
B HEGO sensor
C Sensor shield

4 Remove the sensor heat shield, then unscrew the sensor from the exhaust downpipe, and carefully remove it complete with sealing ring.

Warning: Do not touch the tip of the HEGO sensor.

Refitting
5 Refitting is a reversal of removal, bearing in mind the following points.

6 Clean the sensor threads, and take care not to touch the tip of the sensor during the refitting procedure.

7 Use a new sensor sealing ring.

8 Tighten the sensor to the specified torque.

9 On completion, start the engine and check for leaks between the sensor and the exhaust downpipe.

    See also:

    Contact breaker points adjustment - models with contact breaker distributor (Every 6000 miles or 6 months)
    1 Spring back the retaining clips or undo the screws as appropriate and lift off the distributor cap. 2 Withdraw the rotor arm from the distributor shaft. 3 Using a screwdriver, gently prise the ...

    Inlet manifold - removal and refitting
    Caution: Refer to the precautions in Section 1 before proceeding. Note: A tachometer and an exhaust gas analyser will be required to check the idle mixture on completion. A new gasket must be us ...

    Sump - removal and refitting
    Note: A new gasket and new sump bolts must be used when refitting, and suitable sealant will be required (available from a Ford dealer). Note that it is preferable to keep the engine upright until ...