18 31 030 Replace the catalytic converter (nitrogen oxide catalytic converter) (N47 D20 O 1 with SCR)

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2016 BMW 328i xDrive, 2016 BMW 328d xDrive, 2015 BMW 328i xDrive, 2015 BMW 328d xDrive, and 2014 BMW 328i xDrive. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: Risk of burning!
Only perform this repair work after engine has cooled down.
Danger of injury!
Removal of the exhaust system must be carried out with the assistance of a second person.

Necessary preliminary tasks:

Use a suitable jack to support and protect the nitrogen oxide catalytic converter from falling.
REMOVE MONITORING SENSOR .
Remove the EXHAUST-GAS TEMPERATURE SENSOR from the nitrogen oxide catalytic converter.
Remove rear UNDERBODY PROTECTION .

Release screws (1).

Remove underbody panelling (2).

Fig 1: Identifying Underbody Panelling And Screws

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NOTE: If the separation point is not marked by a punch mark in the pipe, determine the separation point by means of the pipe length on the new front pipe.
Transfer and mark the separation point to the faulty nitrogen oxide catalytic converter.
Protect the nitrogen oxide catalytic converter from falling down.
Cut through exhaust pipes at marked point with a suitable tool and deburr.

Fig 2: Identifying Exhaust Pipe Marked Separation Point

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Release clamp (1).

Tightening torque 18 31 7AZ .

Pull metering unit (2) out of the exhaust system and tie to one side.

Do not disconnect pipes.

Fig 3: Identifying Exhaust System Metering Unit And Clamp

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Slacken nut (1).

Tightening torque 18 20 4AZ .

Fig 4: Identifying Nut

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Detach diesel particulate sensor (1) and place to one side.

Tightening torque 13 62 14AZ .

Detach nitrogen oxide sensor (2) downstream of SCR catalytic converter and place to one side.

Tightening torque 13 62 8AZ .

Fig 5: Identifying Diesel Particulate Sensor And Nitrogen Oxide Sensor

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IMPORTANT: When unscrewing the nitrogen oxide sensor take care that the lead is not damaged.

Release screws (1).

Tightening torque 18 20 6AZ .

Remove reinforcement plate (2).

Fig 6: Identifying Reinforcement Plate And Screws

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Release clamp (1).

Replace clamp (1).

Part: clamp

Tightening torque 18 31 2AZ .

Lower and remove the nitrogen oxide catalytic converter.

Fig 7: Identifying Clamp

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Installation note:

Adjust the new nitrogen oxide catalytic converter and connect with clamps.

Align clamping sleeves so that:

Nuts point downwards.
Cutting line is in middle of clamping sleeve.
There is sufficient spacing to adjoining components.

Fig 8: Identifying Nitrogen Oxide Catalytic Converter
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Center clamp and tighten down.

Tightening torque 18 31 3AZ .

After the repair work has been completed:

Use the BMW Diagnosis System to perform the SCR adjustment.

Refer to:

Service function
SCR systems
Carry out activation and adjustments

Installation note:

Check rubber mount for damage, replace if necessary.

Check exhaust system for leaks.