2.0l - Exhaust System, Emission Controls - Engine Code(s): Caeb (sedan) Audi A4 B8

EXHAUST MANIFOLD

The exhaust manifold and turbocharger are one component; Removing and installing, refer to TURBOCHARGER .

MUFFLER OVERVIEW

Note. The exhaust manifold and turbocharger are one component; Removing and installing, refer to TURBOCHARGER .

Scheme 1

1. Rear Muffler Original equipment as one unit with center muffler. For repairs, replace each separately. Separating point, refer to «CENTER AND REAR MUFFLER, SEPARATING»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__center-and-rear-muffler-separating) Install exhaust system free of stress, refer to «EXHAUST SYSTEM, ALIGNING»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__exhaust-system-aligning)
2. Nut 25 Nm
3. Rear Clamping Sleeve Before tightening, align exhaust system tension-free, refer to «EXHAUST SYSTEM, ALIGNING»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__exhaust-system-aligning) Installed location (Scheme 3)Tighten bolts evenly
4. Bolt 23 Nm
5. Bracket
6. Retaining Loop Replace if damaged
7. Nut 25 Nm
8. Front Clamping Sleeve Before tightening, align exhaust system tension-free, refer to «EXHAUST SYSTEM, ALIGNING»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__exhaust-system-aligning) Installed location (Scheme 2)Tighten bolts evenly
9. Gasket Replace
10. Nut 25 Nm
11. Catalytic Converter Protect catalytic converter from shocks and impact stress Removing and installing, refer to «CATALYTIC CONVERTER»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__catalytic-converter) Install exhaust system free of stress, refer to «EXHAUST SYSTEM, ALIGNING»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__exhaust-system-aligning)
12. Nut 40 Nm Replace Coat turbocharger stud bolts with hot bolt paste. Hot bolt paste, refer to the Parts Information.
13. Gasket Replace
14. Heated Oxygen Sensor (HO2S) -G39- and Oxygen Sensor (O2S) Heater -Z19- Threads of new oxygen sensors are coated with assembly paste When installing a used oxygen sensor, coat threads with hot bolt paste; hot bolt paste, refer to the Parts information. Assembly paste or hot bolt paste must not get onto slots of the oxygen sensor body. Removing and installing, refer to «Removal and Installation»(/audi/a4/b8-2007-2012/remont/fuel-system/#20l-multiport-fuel-injection-engine-codes-caeb-sedan)
15. Oxygen Sensor (O2S) after Three Way Catalytic Converter (TWC) -G130- and Heater for Oxygen Sensor (O2S) 1 after Catalytic Converter -Z29- Threads of new oxygen sensors are coated with assembly paste When installing a used oxygen sensor, coat threads with hot bolt paste; hot bolt paste, refer to the Parts Information. Assembly paste or hot bolt paste must not get onto slots of the oxygen sensor body. Removing and installing, refer to «Removal and Installation»(/audi/a4/b8-2007-2012/remont/fuel-system/#20l-multiport-fuel-injection-engine-codes-caeb-sedan)
16. Front Muffler With flex joint CAUTION: Danger of damaging the decoupling element. Decoupling element must not be bent more than 10°. Do not load decoupling element on cable. Do not damage wire mesh at decoupling element. Depending on the version, there may be a front exhaust pipe installed instead of a front muffler Removing and installing, refer to «FRONT EXHAUST PIPE AND FRONT MUFFLER»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__front-exhaust-pipe-and-front-muffler) Install exhaust system free of stress, refer to «EXHAUST SYSTEM, ALIGNING»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__exhaust-system-aligning)
17. Front Exhaust Pipe With flex joint CAUTION: Danger of damaging the decoupling element. Decoupling element must not be bent more than 10°. Do not load decoupling element on cable. Do not damage wire mesh at decoupling element. Depending on the version, there may be a front exhaust pipe installed instead of a front muffler Removing and installing, refer to «FRONT EXHAUST PIPE AND FRONT MUFFLER»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__front-exhaust-pipe-and-front-muffler) Install exhaust system free of stress, refer to «EXHAUST SYSTEM, ALIGNING»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__exhaust-system-aligning)
18. Bolt 23 Nm
19. Suspended Mount Replace if damaged Check pretension, refer to «EXHAUST SYSTEM, ALIGNING»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__exhaust-system-aligning)
20. Center Muffler Original equipment as one unit with rear muffler. For repairs, replace each separately. Separating point, refer to «CENTER AND REAR MUFFLER, SEPARATING»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__center-and-rear-muffler-separating) Install exhaust system free of stress, refer to «EXHAUST SYSTEM, ALIGNING»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__exhaust-system-aligning)
21. Suspended Mount Replace if damaged Check pretension, refer to «EXHAUST SYSTEM, ALIGNING»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__exhaust-system-aligning)
22. Bolt 23 Nm
23. Exhaust Tailpipe For repairs, replace each separately, refer to «TAILPIPES, REPLACING»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__tailpipes-replacing) Separating point between the rear muffler and the tailpipe, refer to «TAILPIPES, REPLACING»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__tailpipes-replacing)
24. Clamp 60 Nm

Scheme 2

Install clamping sleeve in angle position shown.

1. Threaded connections point toward the right.
2. Nuts face up.
3. α = approximately 20°

Scheme 3

Install the clamping sleeve so that the ends of the bolt do not extend beyond the lower edge of the clamping sleeve.

1. The threaded connections face downward.

FASTENER TIGHTENING SPECIFICATIONS

EXHAUST SYSTEM, CHECKING FOR LEAKS

Start engine and let run at idle.

Seal the tailpipes, for example, with a cloth or a plug, for the duration of the leak test.

Check for leaks by listening at connection areas of cylinder head/exhaust manifold, exhaust manifold/front exhaust pipe etc.

Repair detected leaks.

CATALYTIC CONVERTER

Special tools and workshop equipment required

1. Hose Clamps Up to 25 mm Dia. 3094

Removing

Note. During installation, all cable ties must be installed at the same location.

Disconnect the Oxygen Sensor (O2S) after Three Way Catalytic Converter (TWC) -G130- and Heater for Oxygen Sensor (O2S) 1 after catalytic converter -Z29- connectors and free up the wires.

Scheme 4

Disconnect the Heated Oxygen Sensor (HO2S) -G39- and Oxygen Sensor (O2S) heater -Z19- connectors and free up the wires.

Disconnect the connector -1- from the Mass Airflow (MAF) sensor -G70-.

Scheme 5

Loosen the air intake hose -2-.

Remove the air filter housing upward -arrows-.

Remove the noise insulation. Refer to Description and Operation .

Remove the front exhaust pipe/front muffler. Refer to FRONT EXHAUST PIPE AND FRONT MUFFLER .

Disconnect the threaded connection -1-, remove the bolt -2- and remove the catalytic converter mounting.

Scheme 6

Remove the bolts -arrows- and remove the right drive axle heat shield.

Scheme 7

Remove the nuts -arrows- and remove the catalytic converter upward.

Scheme 8

Installing

Install in reverse order of removal. Note the following

For the correct tightening specifications, refer to MUFFLER OVERVIEW .

Note. Replace seals and self-locking nuts.

Install the front exhaust pipe/front muffler. Refer to FRONT EXHAUST PIPE AND FRONT MUFFLER .

FRONT EXHAUST PIPE AND FRONT MUFFLER

Note. Either a front exhaust pipe or a front muffler is installed, depending on the version.

Removing

Remove the noise insulation. Refer to Description and Operation .

Remove the nuts -arrows-.

Scheme 9

Loosen the threaded connections -arrows-, slide the clamping sleeve to the rear and remove the front exhaust pipe/front muffler.

Scheme 10

Installing

Install in reverse order of removal. Note the following

1. For the correct tightening specifications, refer to «MUFFLER OVERVIEW»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__muffler-overview) .

Note. Replace seals and self-locking nuts.

Install exhaust system free of stress. Refer to EXHAUST SYSTEM, ALIGNING .

Install the noise insulation. Refer to Description and Operation .

CENTER AND REAR MUFFLER, SEPARATING

1. A separating point has been provided in the connecting pipe for individual replacement of the center or rear muffler.
2. The separating point is marked by a depression around the circumference of the exhaust pipe.

Special tools and workshop equipment required

1. Chain Pipe Cutter VAS 6254

Procedure

Separate exhaust pipe at a right angle at separating point -arrows- using the VAS 6254.

Scheme 11

When installing, position the clamping sleeves -arrows- on the center of the separating point

Scheme 12

Install double clamps so that the bolt ends do not project over lower edge of double clamp.

Scheme 13

1. Threaded connection faces toward the left.

Install exhaust system free of stress. Refer to EXHAUST SYSTEM, ALIGNING .

EXHAUST SYSTEM, ALIGNING

Procedure

1. Align exhaust system when cold.
2. Tightening specifications, refer to «MUFFLER OVERVIEW»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__muffler-overview) .

Vehicles Without A Clamping Sleeve Between Center And Rear Mufflers

Loosen the threaded connections on the front clamping sleeve.

Push the exhaust system far enough forward -arrow- until pre-load on rear retaining loops on the rear mufflers is -a- = 6 to 10 mm.

Scheme 14

Align rear muffler horizontally.

Check the distance between the tailpipe and the bumper

Scheme 15

1. Dimension -x- left = dimension -x- right.

Tighten the clamping sleeve threaded connections evenly.

Vehicles with Double Clamps Between Center and Rear Muffler

Loosen the bolts on the front and rear clamping sleeves.

Push the center muffler far enough forward -arrow- until the pre-load on the retaining loops on the center muffler is -a- = 6 to 10 mm.

Tighten the front clamping sleeve threaded connections evenly.

Push the rear muffler far enough forward -arrow- until pre-load on the rear retaining loop on rear muffler is -a- = 11 to 15 mm.

Align rear muffler horizontally.

Check the distance between the tailpipe and the bumper

1. Dimension -x- left = dimension -x- right.

Tighten the rear clamping sleeve threaded connections evenly.

TAILPIPES, REPLACING

Special tools and workshop equipment required

1. Chain Pipe Cutter VAS 6254

1. There is a separating point on each tailpipe if the tailpipe needs to be removed.
2. The separating point is marked by a depression around the circumference of the exhaust pipe.

1. Tightening specifications, refer to «MUFFLER OVERVIEW»(/audi/a4/b8-2007-2012/remont/exhaust/#20l-exhaust-system-emission-controls-engine-codes-caeb-sedan__muffler-overview) .

Separate exhaust pipe at a right angle at separating point -arrows- using the VAS 6254.

Scheme 16

Mount the tailpipes.

Check the distance between the tailpipe and the bumper

1. Dimension -x- left = dimension -x- right.

Tighten the threaded connections on the clamping sleeves.

SPECIAL TOOLS

Special tools and workshop equipment required

Scheme 17

Scheme 18

1. Hose Clamps Up to 25 mm Dia. 3094
2. Chain Pipe Cutter VAS 6254

See also:
• TURBOCHARGER
• Removal and Installation
• Description and Operation
• CENTER AND REAR MUFFLER, SEPARATING
• EXHAUST SYSTEM, ALIGNING
• CATALYTIC CONVERTER
• FRONT EXHAUST PIPE AND FRONT MUFFLER
• TAILPIPES, REPLACING
• MUFFLER OVERVIEW