Remove/install heated O2 sensor - AR07.52-P-5303GZP (ML350, ML550, GL450, GL550)

ENGINE 272, 273 in MODEL 164, 251 

Fig 1: Identifying Heated O2 Sensor Components

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

	Remove/install
	Risk of death  caused by vehicle slipping or toppling off the lifting platform.	Align vehicle between columns of vehicle lift and position four support plates at vehicle lift support points specified by vehicle manufacturer.	AS00.00-Z-0010-01A
	Risk of injury  to skin and eyes caused by handling hot or glowing objects.	Wear safety gloves, protective clothing and safety glasses, if necessary.	AS00.00-Z-0002-01A
1	Turn key in ignition lock to position "0"	Vehicles with Keyless Go, code 889: Press Keyless Go start/stop button repeatedly until ignition is switched off.
2	Remove left catalytic converter	Only required if O2 sensors on the left side should be removed. Installation:  Ensure correct routing of lines on O2 sensors.	AR49.10-P-7100GZA
3	Unclip electrical connector and electrical feed line for corresponding O2 sensor out of retaining clamps on transmission
4	Disconnect electrical connector for corresponding O2 sensor
5	Unscrew corresponding O2 sensor out of catalytic converter completely	Installation:  Coat thread with heat-resistant lubricant.
			*BA14.00-P-1002-01A
			Fig 2
		Paste	*BR00.45-Z-1005-06A
6	Install in the reverse order
7	Read out fault memory and erase if necessary	Stored faults which may be caused by disconnecting cables or by simulation during test operations, must be erased in the fault memory after completing the work. STAR DIAGNOSIS diagnostic system
	Risk of accident  caused by vehicle starting off by itself when engine is running. Risk of injury  caused by contusions and burns during starting procedure or when working near the engine as it is running	Secure vehicle to prevent it from moving by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts.	AS00.00-Z-0005-01A
8	Test run engine and check exhaust system for leaks

O2 SENSOR

Number	Designation		Engine 272	Engine 273
BA14.00-P-1002-01A	O2 sensor to catalytic converter	Nm	50	50

Fig 2: Identifying Box Wrench Bit (000 589 71 03 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

REPAIR MATERIALS

Number	Designation	Order number
BR00.45-Z-1005-06A	Paste, hot lubrication 1 kg, DB supply specification 6879.20	A 000 989 76 51