Discovery 2. Manual — part 462

EMISSION CONTROL - V8

REPAIRS 17-2-47

Sensor - heated oxygen (HO

2

S) - pre-

catalytic converter

$% 19.22.16

Remove

1. Raise vehicle on a ramp.
2. Release HO

2

S multiplug from support bracket.

3. Release HO

2

S harness from clip and

disconnect multiplug from HO

2

S .

4. Using a 22 mm crow's-foot spanner, remove

HO

2

S.

CAUTION: HO

2

sensors are easily damaged

by dropping, excessive heat or
contamination. Care must be taken not to
damage the sensor housing or tip.

Refit

1. Clean sensor and exhaust pipe mating

surfaces.

2. If refitting existing sensor, apply anti-seize

compound to sensor threads.

WARNING: Some types of anti-seize
compound used in service are a health
hazard. Avoid skin contact.

NOTE: A new HO

2

sensor is supplied pre-

treated with anti-seize compound.

3. Fit a new sealing washer to HO

2

S

4. Fit HO

2

S and tighten to 45 Nm (33 lbf.ft).

5. Connect multiplug to HO

2

S, and secure to

support bracket and harness clip.

6. Lower vehicle.

EMISSION CONTROL - V8

17-2-48 REPAIRS

Sensor - heated oxygen (HO

2

S) - post-

catalytic converter

$% 19.22.17

Remove

1. Raise vehicle on ramp.

2. Release HO

2

S multiplug from support bracket.

3. Disconnect HO

2

S multiplug from harness.

4. Using a 22 mm crowsfoot spanner, remove

HO

2

S.

CAUTION: HO2 sensors are easily damaged
by dropping, excessive heat or
contamination. Care must be taken not to
damage the sensor housing or tip.

Refit

1. Clean sensor and exhaust pipe mating

surfaces.

2. If refitting existing sensor, apply anti-seize

compound to sensor threads.

WARNING: Some types of anti-seize
compound used in service are a health
hazard. Avoid skin contact.

NOTE: A new HO2 sensor is supplied pre-
treated with anti-seize compound.

3. Fit a new sealing washer to HO

2

S

4. Fit HO

2

S and tighten to 45 Nm (33 lbf.ft).

5. Connect HO

2

S multiplug to harness and fit

harness to bracket.

6. Secure harness to clip.
7. Lower vehicle.

EMISSION CONTROL - V8

REPAIRS 17-2-49

Control Valve - Secondary Air Injection
(SAI)

$% 17.25.02

Remove

1. Release clip and disconnect air hose from

valve.

2. Disconnect vacuum hose from valve.
3. Remove 2 bolts securing valve to air manifold.
4. Remove valve and discard gasket.

Refit

1. Clean SAI control valve and mating face on

manifold.

2. Fit new gasket and fit valve. Tighten bolts to 10

Nm (7 lbf.ft).

3. Connect vacuum hose.
4. Connect air hose and secure with clip.

Reservoir - Vacuum - Secondary Air
Injection (SAI) - up to 03MY

$% 17.25.04

Remove

1. Disconnect 2 vacuum hoses from reservoir.
2. Remove bolt securing reservoir to mounting

bracket and collect reservoir.

Refit

1. Position reservoir to mounting bracket and

tighten bolt to 10 Nm.

2. Connect vacuum hoses to reservoir.

M17 0222

1

2

3

4

M17 0227

2

1

1

EMISSION CONTROL - V8

17-2-50 REPAIRS

Reservoir - vacuum - Secondary Air
Injection (SAI) - from 03MY

$% 17.25.04

Remove

1. Disconnect 2 vacuum pipes from air reservoir.
2. Remove bolt securing air reservoir to air pump

and remove the reservoir.

Refit

1. Position air reservoir to air pump, fit bolt and

tighten to 10 Nm (7 lbf.ft).

2. Connect vacuum pipes to the air reservoir.

Pump - Air - Secondary Air Injection
(SAI)

$% 17.25.07

Remove

1. Disconnect multiplug from air pump.
2. Release clip and disconnect air hose from air

pump.

3. Remove bolt securing air pump bracket to

body.

4. Remove air pump and bracket assembly.

5. Remove 3 nuts securing bracket to air pump

and collect bracket.

6. Remove 3 mountings from air pump.

Refit

1. Fit mountings to air pump and tighten to 10

Nm.

2. Fit bracket to air pump mountings and tighten

nuts to 10 Nm.

3. Position air pump assembly and tighten bolt to

20 Nm.

4. Connect air hose to SAI pump.
5. Connect multiplug to air pump.

M17 0225

2

1

3

4

M17 0226

5

5

6