Front Exhaust Pipe With Catalytic Converters And Front Muffler

WARNING: This page is about a different car, the 2009 Audi TT and 2008 Audi TT. However, it is still accessible from the selected car via links, so may be relevant.

Removing

-- Remove resonance tube -2- from air guide hose.

Fig 1: Identifying Air Guide Hose, Resonance Tube And Sensor -G70- Electrical Connector

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-- Remove air guide hose -1- from throttle valve control module -J338-.

-- Disconnect the electrical connector -3- for the mass air flow sensor -G70-.

-- Detach upper section of air filter housing -arrow- and remove air filter insert.

-- Remove bolts -arrows- and remove air duct.

Fig 2: Identifying Bolts -Arrows- And Air Guide

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-- Remove lower section of air filter housing -arrows-.

Fig 3: Identifying Screws For Lower Portion Of Air Cleaner Housing

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-- Remove electrical connectors from bracket and disconnect.

-- Free up electrical wires.

Fig 4: Disconnecting Heated Oxygen Sensor (HO2S) Electrical Harness Connector

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For Heated Oxygen Sensor (HO2S) 2 -G108-
For Heated Oxygen Sensor (HO2S) -G39-

NOTE:

Ignore -3-.

-- Remove nuts accessible from above from front exhaust pipe to exhaust manifold connection.

Fig 5: Identifying Exhaust Manifold Nuts

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-- Remove noise insulation in center by loosening mounting parts -1 through 4-.

Fig 6: Center Noise Insulation Fasteners And Center Noise Insulation Panel

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-- Remove nuts -1- and -2- under vehicle floor.

Fig 7: Removing Retaining Screws And Cover

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-- Remove cover from oxygen sensor electrical connector bracket.

-- Remove bolt -3- and free up electrical wiring to oxygen sensors.

-- Remove electrical connectors from bracket and disconnect:

Fig 8: Disconnecting Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) Electrical Harness Connector

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For Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWO) -G130-
For Oxygen Sensor 2 After Catalytic Converter -G131-

-- Remove nuts accessible from below from front exhaust pipe to exhaust manifold connection.

Fig 9: Identifying Exhaust Manifold Nuts

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-- Remove exhaust system bracket and tunnel brace -arrows-.

Fig 10: Identifying Exhaust System Bracket Bolts

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CAUTION:

Risk of damaging decoupling elements.

Do not bend decoupling element in front exhaust pipe more than 10°.

-- Disconnect exhaust system at clamping sleeve -1-.

Fig 11: Identifying Exhaust System Clamping Sleeve

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-- Remove front exhaust pipes with catalytic converters and front muffler.

Installing

Tightening specifications, refer to MUFFLER ASSEMBLY OVERVIEW .

Installation is in reverse order of removal, note the following.

NOTE:

Replace seals and self-locking nuts.

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