Removing and installing/replacing catalytic converter (B46/B48 4-Cyl. Engine) (4' Series Coupe/Convertible, 4' Series Gran Coupe Sedan)

WARNING: Risk of burning!
This repair may only be carried out on an exhaust system which has cooled down .

Necessary preliminary work:

Clamp off BATTERY EARTH LEAD .
Remove FRONT OXYGEN SENSOR .
Remove the MONITORING OXYGEN SENSOR .
Remove front UNDERBODY PROTECTION .
Remove rear UNDERBODY PROTECTION .
Remove EXHAUST SYSTEM .

Removal:

Slacken nut (1).

Feed out B+ cable (2) from the starter motor and set it aside.

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Release positive battery cable (1) from the clamps (2) and lay to one side.

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CAUTION: Do not damage the flexible tube on the catalytic converter. No high bending radius and excessive stretching permitted.

Slacken nut (1).

Release screw (2).

Loosen screws (3).

Feed out holder (4) and remove.

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If installed:

Remove pressure hose (1) in direction of arrow from catalytic converter (2) and set it aside.

Replace pressure hose (1).

Parts: Pressure hose

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Loosen screw (1).

Feed out V-band clamp (2) and remove.

Feed out catalytic converter (3) towards bottom and remove.

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Preparation for installation:

Replace gasket (1) on catalytic converter.

Parts: Gasket

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Replace V-band clamp (1).

Parts: V-band clamp

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Installation:

Feed in and install catalytic converter (3).

Feed in and install new V-clip (2).

Tighten screw (1) hand-tight.

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If installed:

Feed in pressure hose (1) in direction of arrow on the catalytic converter (2) and push on until the limit position is reached.

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Feed in holder (4) and install.

Tighten down screws (3).

Tightening torque 18 31 3AZ .

Tighten nut (1).

Tightening torque 18 31 4AZ .

Tighten screw (2).

Tightening torque 18 31 4AZ .

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Feed positive battery cable (1) into clamps (2) and install.

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Feed in and install positive battery cable (1),

Bring the anti-twist lock (2) of the B+ cable (1) on the starter motor to the limit position (3).

Tighten nut (4).

Tightening torque 12 42 2AZ .

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Tighten the bolt (1) on the V-clip,

Tightening torque 18 31 2AZ .

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Required follow-up work:

Install MONITORING OXYGEN SENSOR .
Install the FRONT OXYGEN SENSOR .
Install EXHAUST SYSTEM .
Install front UNDERBODY PROTECTION .
Install the rear UNDERBODY PROTECTION .
Connect BATTERY EARTH LEAD .