Installing the two catalytic converters

WARNING: This page is about a different car, the 2025 BMW M4, 2024 BMW M4, 2023 BMW M4, 2022 BMW M4, and 2021 BMW M4. However, it is still accessible from the selected car via links, so may be relevant.

Replace V-ribbon clips (1).

Parts: V-ribbon clips

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Replace gasket (1).

Parts: Seal

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Guide in and install catalytic converter (2).
Turn V-ribbon clip (1) until hand-tight .

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Installing the Lambda oxygen sensor for the cylinders 1 to 3

NOTE: TECHNICAL INFORMATION
Grease the threads of new oxygen sensors thinly and evenly.
For oxygen sensors that are reused, the following should be observed:
Thinly and evenly grease the oxygen sensor on the thread only. Do not clean the part of the oxygen sensor that does not protrude into the exhaust line (sensor ceramics) and do not grease.
For additional information see: OVERVIEW OF CONSUMABLES (APPLICABLE BMW PARTS CATALOGUE) (M4 2021-2023) .

Prepare the oxygen sensor.
Do not damage the sensor ceramics.
1. Thread
2. Sensor ceramics
Lightly and evenly grease the thread (1) of the oxygen sensor monitor.

CONSUMABLE DESCRIPTION

Brake block paste * TU = Trade Unit. TU numbers cannot be ordered! For invoicing purposes only.	3 g, Bag 100 g, Tube 5 g, TU*	83192158851 83192158852 83230140233

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Screw in the Lambda oxygen sensor (1) for the cylinders 1 to 3 with a special tool 0 491 074 (11 7 020)and hand-tighten it .

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Tighten the Lambda oxygen sensor (1) for the cylinders 1 to 3 with a special tool 0 491 074 (11 7 020) .

Lambda oxygen sensor on catalytic converter
M18X1.5	tightening torque	50 Nm

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Fasten cable (1) in clamps (arrows).

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Connect connectors (1) and (2) lock.
The connector (1) must engage audibly.
Guide in and install connectors (1) and (2) on carrier plate (3) in the arrow direction.

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Installing the catalytic converter (cylinders 4 to 6)

Replace V-ribbon clips (1).

Parts: V-ribbon clips

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Replace gasket (1).

Parts: Seal

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Guide in and install catalytic converter (1).
Tighten the V-ribbon clip (2) hand-tight.

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NOTE: The following step(s) must be performed if the listed component(s) is/are installed.

Version A:
Insert and install the holder (4).
Tighten the screws (1).

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TIGHTENING TORQUE SPECIFICATIONS

Transmission to engine
M8	Tightening torque	19 Nm


M12	Tightening torque	66 Nm

Replace the screw (2).
Parts: Screw
Tighten down screw (2).

TIGHTENING TORQUE SPECIFICATIONS

Catalytic to holder converter
M8 Replace screw.	Tightening torque	19 Nm

Tighten nut (3).

TIGHTENING TORQUE SPECIFICATIONS

Catalytic converter to holder
M8	Tightening Torque	24 Nm

Version B:
Use special tool 5 A50 FF9 to align and fix the catalytic converter.

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Tighten screws (arrows).

TIGHTENING TORQUE SPECIFICATIONS

Special tool for catalytic converter
M8 screw.	Tightening torque	10 Nm

Align the catalytic converter correctly and tighten the screw (1).

TIGHTENING TORQUE SPECIFICATIONS

Special tool for catalytic converter 2
M18 screw.	Tightening torque	25 Nm

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Tighten the catalytic converter (1) with the V-ribbon clip (2).

TIGHTENING TORQUE SPECIFICATIONS

Catalytic converter to exhaust turbocharger
cl Replace clamp after disassembly.	Tightening torque	14 Nm

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Loosen screw (1).
Remove screws (arrows).

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Remove special tool 5 A50 FF9.

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Install holder (1).

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Installing the oxygen sensor monitor for cylinders 4 to 6

Prepare the oxygen sensor.
The sensor ceramics must not be damaged.
1. Thread
2. Sensor ceramics
Lightly and evenly grease the thread (1) of the oxygen sensor monitor.

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CONSUMABLE DESCRIPTION

Brake block paste * TU = Trade Unit. TU numbers cannot be ordered! For invoicing purposes only.	3 g, Bag	83192158851
	100 g, Tube	83192158852
	5 g, TU*	83230140233

Screw in the oxygen sensor monitor (1) for cylinders 4 to 6 using the special tool 0 491 074 (11 7 020)and hand-tighten (apply) it.

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Tighten (apply) the oxygen sensor monitor (1) for cylinders 4 to 6 using the special tool 0 491 074 (11 7 020) .

TIGHTENING TORQUE SPECIFICATIONS

Oxygen sensor monitor on catalytic converter
M18X1.5	tightening torque	50 Nm

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Secure positive battery cable (2) at the clamp (1).

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Guide in heat shield (2) in the arrow direction and install.
Replace the cable ties (1).
Parts: Cable tie
Feed in and install the cable tie (1).

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Keep the commercially available tools ready.

Number	Description
1	3/8 extension

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Connect the connector (1) with the masking tape (3) to the commercially available tool (2).

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Guide in the commercially available tool (1) with the connector (2) in the arrow direction upwards and position it.

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Thread out the commercially available (1) tool and place it to the side.

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Release the masking tape (1) from the connector (2) and the commercially available tool (3).

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Attach the cable (1) to the clamps (3).
Guide in and install cable (1) on cable duct (2).

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Connect and lock connectors (1) and (2).
The connector (1) must engage audibly.
Guide in the connector (1) and (2) into the carrier plate (3) in the arrow direction and install it.
The connectors (1) and (2) must engage audibly at the carrier plate.

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Fasten the heat shield (1) in the clamp (2).

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Clip the cables (2) into the holders (1).

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Use special tool 5 A50 FF9 to align and fix the catalytic converter.

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Tighten the nuts (arrows).

TIGHTENING TORQUE SPECIFICATIONS

Special tool for catalytic converter 3
Nut	Tightening torque	12 Nm

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Make sure that the catalytic converter lies flush with the mark (1).
Tighten the nuts (arrows).

TIGHTENING TORQUE SPECIFICATIONS

Special tool for catalytic converter 3
Nut	Tightening torque	12 Nm

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Tighten the catalytic converter (2) with the V-ribbon clip (1).

TIGHTENING TORQUE SPECIFICATIONS

Catalytic converter to exhaust turbocharger
cl Replace clamp after disassembly.	Tightening torque	14 Nm

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Unscrew the nuts (arrows).

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Unscrew the nuts (arrows).

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Remove special tool 5 A50 FF9.

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Install the intermediate pipe

NOTE: TECHNICAL INFORMATION
Mount the exhaust system in a de-energized state, following the tightening sequence from the rear silencer towards the exhaust manifold.

Replace the seals (1).

Parts: Seals

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Feed in the intermediate pipe (1) and install it.
Tighten the nuts (arrows).

TIGHTENING TORQUE SPECIFICATIONS

Exhaust system to intermediate pipe on catalytic converter
Nuts M8	Tightening torque Tightening torque	5 Nm 24 Nm

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Version A:

Replace the screw (1).

Parts: Screw

Tighten down screw (1).

TIGHTENING TORQUE SPECIFICATIONS

Exhaust system on the transmission cross member
M8x25 Replace screw.	Tightening Torque	19 Nm

Replace the screw (1).
Parts: Screw

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Tighten down screw (1).

TIGHTENING TORQUE SPECIFICATIONS

Exhaust system on the transmission cross member
M8x25 Replace screw.	Tightening Torque	19 Nm

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Version B:

Replace the screw (1).

Parts: Screw

Tighten down screw (1).

TIGHTENING TORQUE SPECIFICATIONS

Exhaust system on the transmission cross member
M8x25 Replace screw.	Tightening Torque	19 Nm

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Tighten nut (1).

TIGHTENING TORQUE SPECIFICATIONS

Exhaust system to holder
Nut M8	Tightening torque	19 Nm

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Install exhaust system

CAUTION: Component with heavy weight.
Injury hazard!

Note component's center of gravity.
Support component using a jack.
Secure component against falling off the jack.

CAUTION: Heavy component.
Heavy components can lead to injury or damage.

Remove and install heavy components with the aid of another person/other persons.

NOTE: TECHNICAL INFORMATION
Check the exhaust system for tightness after installation.

NOTE: TECHNICAL INFORMATION
Mount the exhaust system in a de-energized state, following the tightening sequence from the rear silencer towards the exhaust manifold.

NOTE: Schematic diagram is for example purposes. Some parts may differ in certain details.

Check all rubber mounts (1) of the exhaust system for damage and replace, if necessary.

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Replace seals (arrows).

Parts: Seals

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NOTE: TECHNICAL INFORMATION
Conduct the following operation with the assistance of a second person.

Insert and install the exhaust system (1) with the help of a support person.

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Tighten nut (1).

TIGHTENING TORQUE SPECIFICATIONS

Rear silencer to bumper bracket
M8	tightening torque	19 Nm

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Tighten nut (1).

TIGHTENING TORQUE SPECIFICATIONS

Rear silencer to bumper bracket
M8	tightening torque	19 Nm

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Tighten nut (1).

TIGHTENING TORQUE SPECIFICATIONS

Exhaust system to rear axle carrier
M8 Nut	tightening torque	19 Nm

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Tighten nut (1).

TIGHTENING TORQUE SPECIFICATIONS

Exhaust system to rear axle carrier
M8 Nut	tightening torque	19 Nm

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Version A:

Replace the screw (1).

Parts: Screw

Tighten down screw (1).

TIGHTENING TORQUE SPECIFICATIONS

Exhaust system on the transmission cross member
M8x25 Replace screw.	Tightening Torque	19 Nm

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Replace the screw (1).
Parts : Screw
Tighten down screw (1).

TIGHTENING TORQUE SPECIFICATIONS

Exhaust system on the transmission cross member
M8x25 Replace screw.	Tightening Torque	19 Nm

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Version B:

Replace the screw (1).

Parts: Screw

Tighten down screw (1).

TIGHTENING TORQUE SPECIFICATIONS

Exhaust system on the transmission cross member
M8x25 Replace screw.	Tightening Torque	19 Nm

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Tighten nut (1).

TIGHTENING TORQUE SPECIFICATIONS

Exhaust system to holder
Nut M8	Tightening torque	19 Nm

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Tighten nuts (1).

TIGHTENING TORQUE SPECIFICATIONS

Exhaust system to catalytic converters/intermediate pipe
M8 Replace nut.	Tightening torque Tightening torque	5 Nm 24 Nm

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Tighten nuts (1).

TIGHTENING TORQUE SPECIFICATIONS

Exhaust system to catalytic converters/intermediate pipe
M8 Replace nut.	Tightening torque Tightening torque	5 Nm 24 Nm

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NOTE: The following step(s) must be performed if the listed component(s) is/are installed.

If necessary, coat the thread of the union nut with assembly paste.

CONSUMABLE DESCRIPTION

High-temperature assembly paste

10 g, Tube

83230309003

Tighten union nuts (1).

TIGHTENING TORQUE SPECIFICATIONS

Pressure line union nut
Pressure line union nut	Tightening torque	40 Nm

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Connect connectors (1) and lock.

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Connect connectors (1) and lock.

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Follow-up work

Refer to INSTALLING THE LAMBDA OXYGEN SENSOR FOR THE CYLINDERS 4 TO 6 .
Refer to INSTALLING THE OXYGEN SENSOR MONITOR FOR CYLINDERS 1 TO 3 .
Refer to INSTALLING THE STIFFENING PLATE .
Refer to INSTALLING THE LEFT AND RIGHT FRONT UNDERSHIELD .
Refer to INSTALLING FRONT UNDERBODY PROTECTION .
Refer to INSTALLING THE FRONT SPOILER .
Refer to INSTALLING THE HOLDER OF THE POSITIVE BATTERY CABLE .
Refer to PARTIALLY INSTALLING THE COOLANT EXPANSION TANK OF THE HIGH-TEMPERATURE COOLANT CIRCUIT .
Refer to INSTALLING THE RIGHT INTAKE FILTER HOUSING (FRONT-END STRUT REMOVED) .
Refer to INSTALLING THE FRONT-END STRUT .
Refer to INSTALLING ACOUSTIC COVER .
Refer to INSTALLING THE STRUT BRACE .
Refer to INSTALLING THE FRONT HOOD SEAL .
Refer to TAKING HOOD OUT OF THE SERVICE POSITION .