18 32 510 Removing and installing/replacing left or right catalytic converter (M62): Installation:

WARNING: This page is about a different car, the 2003 BMW X5, 2002 BMW X5, 2001 BMW X5, and 2000 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.

Nuts point downwards.

Align clamping sleeves so that:

separation point is in middle of clamping sleeve, and
there is sufficient spacing to adjoining components.

Fig 1: Connecting New Catalytic Converter And Center Muffler Using Clamping Sleeves
Courtesy of BMW OF NORTH AMERICA, INC.

NOTE: Do not clean oxygen and monitor sensors and do not bring into contact with lubricant.
Protect oxygen and monitor sensors when applying underbody protection.

Unscrew oxygen and monitor sensor from old catalytic converter. If necessary, replace oxygen and monitor sensor.

Tightening torque, see 11 78 1AZ in ENGINE - TIGHTENING TORQUES .

Coat thread with grease for oxygen sensor.

Screw oxygen and monitor sensor onto new catalytic converter.

Fig 2: Removing Oxygen And Monitor Sensor From Old Catalytic Converter

Courtesy of BMW OF NORTH AMERICA, INC.