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.
1. Remove right or left rear wheel. -> 44051900 Removing and installing wheel - section on "Removing" 44051900 Removing and installing wheel.
2. Remove rear wall cover. -> 555919 Removing and installing rear wall cover - section on "Removing" 555919 Removing and Installing Rear Wall Cover.
3. Remove engine compartment lid. -> 557819 Removing and installing engine compartment lid - section on "Removing".
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
- Risk of damage to oxygen sensors
- Different exhaust emission behaviour
-> 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. Open plug connection for oxygen sensor (blue cable).
1.1. Unclip cable plug and connecting cable from the holder. For cylinder bank 1-3, see illustration -1- , for cylinder bank 4-6, see illustration -1-.
Plug connection for right oxygen sensor on inner sill (cylinder bank 1-3)
Plug connection for left oxygen sensor on inner sill (cylinder bank 4-6)
1.2. Release and disconnect cable plug.
2. Expose connecting cable on the cylinder head as far as the oxygen sensor upstream of the catalytic converter.
2.1. Take photographs of the line routing using a digital camera if necessary.
2.2. Cut tie-wraps on the line if necessary.
3. Remove oxygen sensor upstream of catalytic converter -arrow-.
Oxygen sensor upstream of catalytic converter
3.1. Make sure that the connecting cable can also turn when removing the oxygen sensor.
Installing oxygen sensor upstream of catalytic converter
NOTICE
Incorrect handling of oxygen sensors
- Risk of damage to oxygen sensors
- Different exhaust emission behaviour
-> 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 Service and Repair.
1. Visually check the sealing ring -arrow- and thread on the oxygen sensor for damage.
1.1. Replace oxygen sensor if damaged.
Oxygen sensor thread
2. Fit oxygen sensor.
2.1. Grease thread of oxygen sensor with a light coating of Optimol Paste MF (000.043.207.07) before refitting. New oxygen sensors are pre-greased for installation.
2.2. Fit and screw in oxygen sensor by hand. => Oxygen sensor upstream of catalytic converter
Oxygen sensor upstream of catalytic converter
2.3. Make sure that the connecting cable can also turn when installing the oxygen sensor.
2.4. Tighten oxygen sensor using accessory for torque wrench: angled open-end/ring wrench Nr.96-3.
=> Tightening torque: 50 Nm (37 ftlb.)+/-8 Nm (+/-6 ftlb.)
3. Route blue connecting cable as far as the oxygen sensor and clip it into the holders. Replace tie-wraps if necessary.
4. Fit plug connection for oxygen sensor.
4.1. Clip cable plug and connecting cable into the holder. For cylinder bank 1-3, see illustration -1- , for cylinder bank 4-6, see illustration -1-.
Plug connection for right oxygen sensor on inner sill (cylinder bank 1-3)
Plug connection for left oxygen sensor on inner sill (cylinder bank 4-6)
4.2. Connect and lock cable plug.
Subsequent work
1. Install right or left rear wheel. -> 44051900 Removing and installing wheel - section on "Installing" 44051900 Removing and installing wheel.
2. Install rear wall cover. -> 555919 Removing and installing rear wall cover - section on "Installing" 555919 Removing and Installing Rear Wall Cover.
3. Install engine compartment lid. -> 557819 Removing and installing engine compartment lid - section on "Installing".
4. Read out the fault memory and correct any faults that are present, then erase the fault memory. -> 033500 On-board diagnosis - section on "Reading out" 033500 On-board diagnosis (OBD).