Muffler Overview

Fig 1: Muffler Overview

Courtesy of AUDI OF AMERICA, LLC

1. Center Muffler
   • Original equipment as one unit with rear mufflers. For repairs, replace each separately
   • Separating point, refer to EXHAUST PIPES/MUFFLERS, SEPARATING .
   • Align the exhaust system free of tension, refer to EXHAUST SYSTEM, INSTALLING WITHOUT TENSION .
2. Rear Muffler
   • Original equipment as one unit with center muffler and tailpipe
   • The center muffler and the rear muffler can be replaced individually if a repair is required.
   • Separating point between the center and rear muffler, refer to EXHAUST PIPES/MUFFLERS, SEPARATING .
   • Align the exhaust system free of tension, refer to EXHAUST SYSTEM, INSTALLING WITHOUT TENSION .
   • With exhaust door and Exhaust Door Valve 1 -N321-, refer to Fig 6
   • Exhaust Door Valve 1 - N321-, removing and installing, refer to EXHAUST DOOR VALVE 1 -N321-, REMOVING AND INSTALLING 
3. Seal
   • Replace
4. Seal
   • Replace
5. Nut
   • 20 Nm
   • Replace
   • Coat the thread with hot bolt paste .
6. Catalytic Converter
   • Protect from shocks and impact stress
   • Removing and installing, refer to CATALYTIC CONVERTER, REMOVING AND INSTALLING .
   • Individual suspension components, refer to Fig 4, Fig 5
7. Nut
   • 20 Nm
   • Replace
   • Coat the thread with hot bolt paste .
8. Suspended Mount
   • Replace if damaged
   • Check pretension, refer to EXHAUST SYSTEM, INSTALLING WITHOUT TENSION .
9. Bolt
   • 23 Nm
10. Front Muffler
    • With decoupling element, decoupling element must not be bent more than 10° - otherwise it may be damaged
    • Removing and installing, refer to FRONT MUFFLER, REMOVING AND INSTALLING .
    • Align the exhaust system free of tension, refer to EXHAUST SYSTEM, INSTALLING WITHOUT TENSION .
11. Front Clamping Sleeve
    • Installed position, refer to Fig 2
    • Before tightening, align exhaust system free of tension, refer to EXHAUST SYSTEM, INSTALLING WITHOUT TENSION .
    • Tighten threaded connections evenly.
12. Nut
    • 23 Nm
13. Hood
    • For the tail pipe
    • Push all the way onto the tail pipe
14. Suspended Mount
    • Replace if damaged
    • Check pretension, refer to EXHAUST SYSTEM, INSTALLING WITHOUT TENSION .
15. Nut
    • 23 Nm
16. Rear Clamping Sleeve
    • For individual replacement of center and rear mufflers
    • Installed position, refer to Fig 2
    • Before tightening, align exhaust system free of tension, refer to EXHAUST SYSTEM, INSTALLING WITHOUT TENSION .
    • Tighten threaded connections evenly.
17. Nut
    • 23 Nm
18. Suspended Mount
    • Replace if damaged
    • Check pretension, refer to EXHAUST SYSTEM, INSTALLING WITHOUT TENSION .
19. Bolt
    • 23 Nm
20. Suspended Mount
    • Replace if damaged
    • Check pretension, refer to EXHAUST SYSTEM, INSTALLING WITHOUT TENSION .

Fig 2: Installed Position of Front Double Clamps

Courtesy of AUDI OF AMERICA, LLC

• Installed position: the threaded connectors face outward.
• Angle -α- = 45°.

Fig 3: Identifying Installed Position Of Rear Double Clamps

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

• Installed position: the threaded connectors face forward.

Fig 4: Individual Left Catalytic Converter Mounting Components

Courtesy of AUDI OF AMERICA, LLC

1. Bolt - 23 Nm
2. Bracket
3. Tab
4. Rubber buffer
5. Spacer Sleeve
6. Bolt - 23 Nm
7. Bolt - 23 Nm
8. Washer
9. Pressure Spring
10. Spacer Sleeve
11. Nut

Fig 5: Individual Right Catalytic Converter Mounting Components.

Courtesy of AUDI OF AMERICA, LLC

1. Spacer Sleeve
2. Tab
3. Rubber buffer
4. Spacer Sleeve
5. Bolt - 23 Nm
6. Bolt - 23 Nm
7. Washer
8. Pressure Spring
9. Spacer Sleeve
10. Nut

Fig 6: Exhaust Door and Exhaust Door Valve 1 -N321-

Courtesy of AUDI OF AMERICA, LLC

1. Vacuum diaphragm for exhaust door
2. Bolts - 5.5 Nm
3. Exhaust Door Valve 1 -N321-
4. vacuum hose to the vacuum diaphragm
5. vacuum hose from the engine
6. Cable ties