Remove/install heated O2 sensor - AR07.52-P-5303RKA

ENGINE 276 in MODEL 231 

Shown on left side 

Fig 1: Heated O2 Sensor Remove/Install Components - Shown On Left Side

Courtesy of MERCEDES-BENZ USA

Shown on right-hand side 

Fig 2: Heated O2 Sensor Remove/Install Components - Shown On Right-Hand Side

Courtesy of MERCEDES-BENZ USA

	Risk of injury  caused by fingers being jammed or pinched when removing, installing or aligning hoods, doors, trunk lid/rear-end door or sliding roof.	No parts of the body or limbs should be within the operating area when the components are moving.	AS00.00-Z-0011-01A
	Risk of injury.  Skin or eye injuries may result when handling hot or glowing objects.	Wear protective gloves, protective clothing and safety glasses, if necessary.	AS00.00-Z-0002-01A
	Risk of death  caused by vehicle slipping or toppling off of the lifting platform.	Align vehicle between vehicle lift columns and position the four support plates at the vehicle lift support points specified by the vehicle manufacturer.	AS00.00-Z-0010-01A
	Risk of injury  caused by scraping or cutting body parts on sharp vehicle parts	Always wear protective gloves when working on or near sharp and non-deburred vehicle parts. Deburr repair panels.	AS00.00-Z-0017-01A
	Notes on self-locking nuts and bolts		AH00.00-N-0001-01A
	Notes on avoiding damage through contamination and foreign objects		AH00.00-P-5000-01A
	Remove/install
1.1	Switch off ignition and remove transmitter key	Engine 276 in model 231 except code 889 (KEYLESS-GO)
1.2	Actuate KEYLESS GO start/stop button	Engine 276 in model 231 with code 889 (KEYLESS-GO)
2	Remove lower engine compartment paneling		AR61.20-P-1105RK
	Remove oxygen sensor on left or right downstream of CAT (G3/5 or G3/6)
3	Remove screw/bolts (2) and remove bracket (1) between left exhaust manifold (3) or right exhaust manifold (4) and remove transmission housing	Engine 276.9 in model 231 Bolt, bracket for front exhaust system to exhaust system/transmission	*BA49.10-P-1002-01AM
4	Disconnect electrical connection for left oxygen sensor downstream of CAT (G3/5x1) or electrical connection for right oxygen sensor downstream of CAT (G3/6x1)
5	Unclip electrical line for left or right oxygen sensor downstream of CAT (G3/5 or G3/6) from retaining clamps () and bracket	Ensure respective electrical wiring harness is correctly routed.
6	Remove oxygen sensor on left or right downstream of CAT (G3/5 or G3/6)	Coat thread with hot lubrication paste.
		Oxygen sensor downstream of catalytic converter	*BA14.00-P-1004-01A
		Paste, hot lubrication 1 kg, DBL 6879.20	*BR00.45-Z-1005-06A
		Box wrench bit	Fig 3
	Remove left oxygen sensor upstream of catalytic converter (G33)
7.1	Remove front upper engine cover	Engine 276.9 in model 231
7.2	Remove upper engine cover	Engine 276.8 in model 231
8	Remove left air filter housing	Engine 276.8 in model 231	AR09.10-P-1150RKA
9	Remove ME-SFI [ME] control unit	Engine 276.9 in model 231	AR07.08-P-7008RKA
10	Disconnect electrical connection for left oxygen sensor upstream of catalytic converter (G33x1)
11	Unclip electrical line for oxygen sensor upstream of catalytic converter (G3/3) out of retaining clips and bracket	Ensure that electrical wiring harness is routed properly.
12	Remove left oxygen sensor upstream of catalytic converter (G33)	Coat thread with hot lubrication paste.
		Oxygen sensor upstream of catalytic converter	*BA14.00-P-1005-01A
		Box wrench bit	Fig 3
	Remove right oxygen sensor upstream of catalytic converter (G3/4)
13.1	Remove air filter housing	Engine 276.9 in model 231
		Screw/bolt, air filter to cylinder head cover	*BA09.10-P-1001-01M
		Screw/bolt, air filter to air intake pipe support brace	*BA09.10-P-1002-01M
13.2	Remove right air filter housing	Engine 276.8 in model 231	AR09.10-P-1150RKA
14	Disconnect electrical connection for right oxygen sensor upstream of catalytic converter (G3/4x1)
15	Unclip electrical line for oxygen sensor on the right upstream of catalytic converter (G3/4) out of retaining clips and bracket	Ensure that electrical wiring harness is routed properly.
16	Remove oxygen sensor on the right upstream of CAT (G3/4)	Coat thread with hot lubrication paste.
		Oxygen sensor upstream of catalytic converter	*BA14.00-P-1005-01A
		Paste, hot lubrication 1 kg, DBL 6879.20	*BR00.45-Z-1005-06A
		Box wrench bit	Fig 3
17	Install in the reverse order
18	Connect STAR DIAGNOSIS, read out fault memory
			AD00.00-P-2000-04A
	Check
	Risk of accident  from vehicle starting off by itself when engine running. Risk of injury  (bruises and burns) resulting from working on the engine while it is being started or when it is running.	Secure vehicle to prevent it from starting off by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts.	AS00.00-Z-0005-01A
19	Carry out an engine test run and check exhaust system for leaktightness

Fig 3: Identifying Box Wrench Bit (000 589 71 03 00)

Courtesy of MERCEDES-BENZ USA