18 32 050 Removing and installing/replacing catalytic converter (N55)

WARNING: Risk of burning!
Only perform this repair work after the exhaust system has cooled down.

Necessary preliminary tasks:

Remove front UNDERBODY PROTECTION .
Remove rear underbody protection . See 51 47 490 REMOVING AND INSTALLING/REPLACING FRONT UNDERBODY PROTECTION or 51 47 490 REMOVING AND INSTALLING/REPLACING FRONT UNDERBODY PROTECTION (AWD) .
Remove EXHAUST SYSTEM .
Four-wheel drive vehicles only:
Remove right ENGINE MOUNT .

Remove right ENGINE SUPPORT ARM .

REMOVE MONITORING SENSOR .

NOTE: The oxygen sensor is in danger of being damaged when the catalytic converter is removed and installed.

Remove the control sensor . See 11 78 510 REPLACING OXYGEN CONTROL SENSOR (N55) or 11 78 510 REPLACING OXYGEN CONTROL SENSOR (N55) .

IMPORTANT: To remove the control sensor in all-wheel drive vehicles, the drive shaft must not be removed if the necessary preliminary work for the catalytic converter was performed!

Release nuts (1).

Tightening torque 18 20 2AZ .

Fig 1: Identifying Catalytic Converter Mounting Nut

Courtesy of BMW OF NORTH AMERICA, INC.

Release clamp (1). The clamp must be renewed every time it is removed.

Tightening torque 18 31 3AZ .

In so doing, secure catalytic converter against falling out.

Feed out catalytic converter and remove.

Installation note:

Clean sealing surface. Renew clamp and seal.

Only for vehicles with rear-wheel drive

When replacing the catalytic converter, convert MONITORING SENSOR .

Fig 2: Identifying Catalytic Converter Clamp

Courtesy of BMW OF NORTH AMERICA, INC.

Reassemble the vehicle.

Check exhaust system for leaks.