246919 Removing and installing oxygen sensors upstream of catalytic converter

WM 246919 Removing and installing oxygen sensors upstream of catalytic converter

Tools

Technical values

Preliminary work

WARNING

Objects or loads falling down

- Risk of squashing or crushing

-> Secure components to prevent them from falling down.

Information

- When lowering, the engine must not rest on the rear axle cross member.

1. Remove air cleaner housing.
=> 242519 Removing and installing air cleaner housing.
2. Open oxygen sensor connectors in engine compartment.
The sensor connectors and cables are of different colors.

2.1. Open connector on left; to do so pull the two connectors out of the holder and then release them.
Unclip cable -arrow-.

Oxygen sensor plug connections on side 1-3

2.2. Open connector on right; to do so pull the two connectors out of the holder and then release them.
Unclip cable -arrows-.

Oxygen sensor plug connections on side 4-6

3. Remove rear wheel. Use special tool Socket-wrench insert P300.
=> 44051900 Removing and installing wheel.

Removal

Removing oxygen sensor upstream of catalytic converter

CAUTION

Hot components

- Risk of burns

-> Let hot components cool down.
-> Wear personal protective gear.

NOTICE

Incorrect handling of oxygen sensors

- Damage to oxygen sensors
- Different exhaust emission behavior

-> Do not remove the plastic cap on the thread until just prior to fitting.
-> Protect oxygen sensors from impact of any kind.
-> Do not kink or twist the cables when screwing in the sensors.
-> Do not re-use dirty or damaged components.

1. Observe instructions when working with oxygen sensors.
=> 2400AW Precautionary measures when handling oxygen sensors.

Installation position of oxygen sensors on side 1-3

Oxygen sensors on side 1-3

Oxygen sensors on side 4-6

2. Unclip cable for oxygen sensor upstream of catalytic converter (blue) at the mounting points (item 6).
3. Loosen and unscrew oxygen sensor -1-.
3.1. Tool recommendation: Torque wrench with open-jawed wrench insert Nr.95 -2-.

Using tool for oxygen sensor

Installation

Installing oxygen sensor upstream of catalytic converter

NOTICE

Incorrect handling of oxygen sensors

- Damage to oxygen sensors
- Different exhaust emission behavior

-> Do not remove the plastic cap on the thread until just prior to fitting.
-> Protect oxygen sensors from impact of any kind.
-> Do not kink or twist the cables when screwing in the sensors.
-> Do not re-use dirty or damaged components.

Information

- Before installing the oxygen sensors, check that the cover plates are fitted on the catalytic converters.

- If not, retrofit them in accordance with Technical Information => 261324 Fault codes P0421/ P0431: Warm up Catalyst Efficiency Below Threshold (28/09).

- The installation is described in the PIWIS information system under => 261319 Removing and installing exhaust manifold cover plate.

1. Observe instructions when working with oxygen sensors.
=> 2400AW Precautionary measures when handling oxygen sensors.

Information

- When reinstalling oxygen sensors, grease the thread with the Optimol Paste MF lubricant (Part No. 000.043.207.07) only.

- New oxygen sensors have already been greased and the thread is fitted with a protection cap.

2. During reinstallation of the oxygen sensor, the thread must be coated with the prescribed lubricant.
2.1. New oxygen sensors are pre-greased for installation.
3. Screw in oxygen sensor -1- by hand and tighten it to tightening specification.
Tool recommendation: Torque wrench with open-jawed wrench insert Nr.95 -2-.

Using tool for oxygen sensor

=> Tightening torque: 50 Nm (37 ftlb.)+/-8 Nm (+/-6 ftlb.)
4. Route oxygen sensor cable (blue) along the engine and secure it at the defined mounting points (see overview diagrams, item 6).

Subsequent work

WARNING

Objects or loads falling down

- Risk of squashing or crushing

-> Secure components to prevent them from falling down.

1. Route oxygen sensor cable in engine compartment and secure in the retaining clips.
1.1. Close plug connections and insert into the holders.
2. Install air cleaner housing.
=> 242519 Removing and installing air cleaner housing.
3. Mount rear wheel.
=> 44051900 Removing and installing wheel.