Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Oxygen Sensor: Service and Repair

REMOVAL AND INSTALLATION <3.8L ENGINE>



Pre-removal Operation And Post-Installation Operation:




Removal Steps 1 - 11:





Required Special Tools:
- MB991953: Oxygen Sensor Wrench
- MD998770: Oxygen Sensor Wrench



Pre-removal Operation And Post-Installation Operation:




Removal Steps 1 - 3:








Required Special Tools:
- MB991953: Oxygen Sensor Wrench
- MD998770: Oxygen Sensor Wrench

REMOVAL SERVICE POINTS

<> LEFT BANK HEATED OXYGEN SENSOR (FRONT)/RIGHT BANK HEATED OXYGEN SENSOR (FRONT) REMOVAL




Use special tool MD998770 to remove the heated oxygen sensor.

<> LEFT BANK HEATED OXYGEN SENSOR (REAR)/RIGHT BANK HEATED OXYGEN SENSOR (REAR) REMOVAL




Use special tool MB991953 to remove the heated oxygen sensor.

INSTALLATION SERVICE POINTS

>>A<< RIGHT BANK HEATED OXYGEN SENSOR (REAR)/LEFT BANK HEATED OXYGEN SENSOR (REAR) INSTALLATION




Use special tool MB991953 to install the heated oxygen sensor.

>>B<< RIGHT BANK HEATED OXYGEN SENSOR (FRONT)/LEFT BANK HEATED OXYGEN SENSOR (FRONT) INSTALLATION




Use special tool MD998770 to install the heated oxygen sensor.

INSPECTION
Check the following points; replace the part if a problem is found.

Exhaust Manifold Check
1. Check for damage or cracking of any part.
2. Using a straight edge and a feeler gauge, check for distortion of the cylinder head installation surface.

Standard value: 0.15 mm (0.006 inch) or less
Limit: 0.20 mm (0.008 inch)