AUDI A4 1998 B5 / 1.G AHA ATQ Engines Exhaust System Components Manual

26-1


Exhaust system components,
removing and installing

WARNING!

Do not re-use any fasteners that are worn or
deformed in normal use.
Some fasteners are designed to be used only
once, and are unreliable and may fail if used
a second time. This includes, but is not
limited to, nuts, bolts, washers, circlips and
cotter pins. Always follow the
recommendations in this manual-replace
these fasteners with new parts where
indicated, and any other time it is deemed
necessary by inspection.

Notes:
Always replace gaskets and self-locking nuts.
After exhaust system repairs, make sure
exhaust system is not under stress and that it
has sufficient clearance from the bodywork. If
necessary, loosen double clamps and align
muffler and and exhaust pipe so that sufficient
clearance is maintained to the bodywork and
the support rings are evenly loaded.

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The flexpipe in left and right exhaust pipes must
not be bent more than 10 , otherwise it may be
damaged.
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26-2


Exhaust manifold, front exhaust pipe and
Three Way Catalytic Converter (TWC) with
attachments

1 -
Spacer sleeve
2 -
Bolt
3 -
Washers
4 -
Bracket
5 -
Spacer bushing
6 -
Rubber bushing
7 -
25 Nm (18 ft lb)
8 -
Spring
9 -
Bolt
25 Nm (18 ft lb)
10 -
To center muffler
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26-3


CAUTION!
Part numbers are listed here for reference only.
Always check with your Parts department for
the latest information. 11 -
Left-front exhaust pipe with Three Way
Catalytic Converter (TWC)
The flexpipe in left and right exhaust pipes
must not be bent more than 10 , otherwise
it may be damaged
12 -
Heated Oxygen Sensor (HO2S) 2 -G108-
50 Nm (37 ft lb)Only grease threads using "G5" ("G5" must
not get into slots on body of sensor) Checking DTC memory Repair Manual,
2.8 Liter V6 5V Fuel Injection & Ignition,
Repair Group 01 Checking components and heating function
Repair Manual, 2.8 Liter V6 5V Fuel
Injection & Ignition, Repair Group 24
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26-4


13 -
4-pin harness connectors
BlackMounted to bulkheadFor Heated Oxygen Sensors (HO2S) and
for heating function
14 -
25 Nm (18 ft lb)
15 -
Cover cap 10 Nm (7 ft lb)
16 -
Connection
17 -
Upper heat shield
18 -
Lower heat shield
19 -
Left-side exhaust manifold
20 -
Gaskets Always replace
21 -
Right-side exhaust manifold
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26-5


CAUTION!
Part numbers are listed here for reference only.
Always check with your Parts department for
the latest information. 22 -
Heated Oxygen Sensor (HO2S) -G39-
50 Nm (37 ft lb)Only grease threads with "G5" ("G5" must
not get into slots on body of sensor) Checking DTC memory Repair Manual,
2.8 Liter V6 5V Fuel Injection & Ignition,
Repair Group 01 Checking components and heating
function Repair Manual, 2.8 Liter V6 5V
Fuel Injection & Ignition, Repair Group 24
23 -
Right-front exhaust pipe with Three Way
Catalytic Converter (TWC)
The flexpipe in left and right exhaust pipes
must not be bent more than 10 , otherwise
it may be damaged
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26-6


Mufflers with mounts

Vehicles with all-wheel drive
Vehicles with front-wheel-drive page 26
-9 .
1 -
40 Nm (30 ft lb)
2 -
From Three Way Catalytic Converter
(TWC)
3 -
Carriage bolts
4 -
Double clamp
5 -
25 Nm (18 ft lb)
6 -
Mounts
With retaining ring
7 -
Center muffler
8 -
Double clamp (for repair)
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26-7


9 -
Separating points
At factory, center and rear mufflers are
installed as single component.
Replacement center and rear mufflers are
supplied separately, with double clamp for
connecting joint Cutting through at separating point Fig. 1
10 -
Right-rear muffler
11 -
Mounts
12 -
Brackets
13 -
Left-rear muffler
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26-8


Cutting Fig. 1 Separating point between front and rear mufflers
- Using VAG1523 body saw, cut through connecting pipe between
center muffler and rear muffler at groove.
Distance -a-: approx. 244 mm (9-1/2 in.).
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26-9


Vehicles with front wheel drive
1 -
40 Nm (30 ft lb)
2 -
From Three Way Catalytic Converter
(TWC)
3 -
Carriage bolts
4 -
Double clamps
5 -
25 Nm (18 ft lb)
6 -
Mounts
With retaining ring
7 -
Center muffler
8 -
Bracket
9 -
Mount
10 -
Rear muffler
11 -
Double clamp (for repair)
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