catalytic converter JAGUAR X308 1998 2.G Owner's Guide

Exhaust System -
Torques


ComponentNm
Nut - Downpipe catalytic converter to exhaust manifold14 - 18
Bolt - Downpipe catalytic converter to lower mounting bracket39 - 51
Bolt - Front muffler mounting to gearbox (SC)22 - 28
Bolt - Front muffler mounting to front muffler cross brace (SC)22 - 28
Bolt - Over-axle mounting to rear suspension A-frame22 - 28
Torca clamps52 - 68
Oxygen sensor to downpipe40 - 50

All vehicles are fitted with a stainless steel exhaust system which features:
Low back-pressure gas flow. Catalytic converters for mark ets having unleaded fuel. Front muffler common to the left-hand and right-hand engine cylinder banks.
Downpipe Catalytic Converter Assembly

The left-hand and right-hand do wnpipe assemblies feature:
Catalytic converter with palladium / rhodium coated elem ents. The elements are uncoated for markets with only
leaded fuel.
Retained to the exhaust manifold flange by four thread ed studs. Joint-to-joint sealing is with a gasket. Engine-mounted bracket providing downpipe mounting by two nuts to the torque converter housing and two bolts to
the downpipe.
Front Muffler Assembly
ItemPart NumberDescription
1—Downpipe catalytic converter
2—Upstream heated oxygen sensor
3—Downstream oxygen sensor (North American markets only)
4—Engine mounting bracket (LHS and RHS)

Parts List
Operation
ItemPart NumberDescription
1—Heated oxygen sensor (upstream)
2—Oxygen sensor (downstream)
3—Catalytic converter

The upstream heated oxygen sensor is located at the catalytic converter inlet and detects the concentration of oxygen in the
raw exhaust gases; an internal heater reduces the warm up time of the sensor output.
An oxygen sensor (without heater) is located at the converter outlet.
The ECM receives input signals from the se nsors and varies the fuel injector duration (mixture) to provide optimum gas
emissions.
Circuit Diagram, O2 Sensors / ECM

Exha
ust System - Catalyti
c Converter LH4.0L NA V8 - AJ27/3.2L NA V8 -
AJ26
Re mo
val and Installation
Remova

l
1.
Op
en the engine compartment and fit paintwork protection
sheets.
2. Remove the front muffler; refer to Operation 30.10.18 in this
section.

3. Re
move the centre trim panel
from the engine compartment.
1. Remove the left hand side enclosure panel.
2. Remove the centre trim panel.

4. Repo
sition the expansion tank from the mounting.
1. Disconnect the coolant level sensor connector.
2. Remove the nuts which secures the tank.

5. CAUT
ION: Note the position of the upstream and
downstream (where fitted) o xygen sensor multiplugs for
reassembly.
Disconnect the oxygen sensor multiplugs.
Di spl
ace the multiplugs from the engine mounting bracket.

Dis
connect the plug(s) from the oxygen sensor(s)
6.
Re
move the four nuts which se
cure the downpipe catalytic
converter to the exhaust manifold.

I
nstallation

7.
R
aise the vehicle on a ramp.

8. R
emove the downpipe catalytic converter.
R

emove the bolts which se
cure the downpipe lower
mounting bracket.
Remove the
downpipe assembly.

9. R
emove the oxygen sensor(s).
The downstream sensor i

s fitt
ed only for North American
markets.
10. Remove gasket from the manifold flange.
Clean and inspect th
e manifold joint faces.
Clean and inspect th

e threads
on the downpipe studs.
1. Fit the oxygen sensor(s).
The downstream sensor i
s fitt
ed only for North American
markets.

2. Fit a ne
w gasket to the mani
fold mating flange on the
downpipe.

3. Fit
the downpipe catalytic converter.
Fit the down
pipe assemb l
y to the manifold.
Fi
t,
but do not fully tighten, the mounting bracket securing

bolts. (Leave loose until the nu ts securing the downpipe to
the exhaust manifold are fitted.)
4. Lower the ramp.

5. Tighte
n the nuts securing the downpipe flange to the manifold
flange.

6. Connec t
the oxygen sensor multiplugs.
Con
n
ect the plug(s) to the respective (previously noted)
sensor(s).
Cor r
ectly position the multiplu
gs on the mounting bracket.
7. Fit the coolant header tank.
1. Reposition the tank and fit the securing nuts.

Exha
ust System - Catalytic Conv
erter LH4.0L SC V8 - AJ26
Remo
val and Installation
Remov
a
l
1.
Op
en the engine compartment and fit paintwork protection
sheets.

2. Re
move the centre trim panel
from the engine compartment.
1. Remove the left hand side enclosure panel.
2. Remove the centre trim panel.

3. Repo
sition the expansion tank from the mounting.
1. Disconnect the coolant level sensor connector.
2. Remove the nuts which secures the tank.

4. CAUT
ION: Note the position of the upstream and
downstream (where fitted) o xygen sensor multiplugs for
reassembly.
Disconnect the oxygen sensor multiplugs.
Di spl
ace the multiplugs from the engine mounting bracket.

Dis
connect the plug(s) from the oxygen sensor(s)

5.
Re
move the four nuts which se
cure the downpipe catalytic
converter to the exhaust manifold.

6. R
aise the vehicle on a ramp.

7. R
emove the bolts which secure
the rear of the front muffler
assembly to the transmission rear mounting.

8. R
emove the bolts which secure
the front flange of the front
muffler to the downpipe flange.
R
epeat for the flange bolt
s on the opposite side.

9. R
emove the gasket from the front
muffler flange at each side.
R
eposition the front silencer rearwards.
R

emove the gasket from each flange.

10
.
Remove the downpipe catalytic converter.
R
emove the bolts which se
cure the downpipe lower
mounting bracket.
Remove the
downpipe assembly.
11. Remove the oxygen sensor(s).
The downstream sensor i
s fitt
ed only for North American
markets.