Remove/Install Heated O2 Sensor - AR07.52-P-5303GQC

ENGINE 276.8 in model 166, 251, 292 

Fig 1: Left Heated O2 Sensor Components Location - Engine 276.8 In Model 166

Courtesy of MERCEDES-BENZ USA

Shown on ENGINE 276.8 in model 166 

Fig 2: Right Heated O2 Sensor Components Location - Engine 276.8 In Model 166

Courtesy of MERCEDES-BENZ USA

Shown on ENGINE 276.8 in model 166 

	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
	Remove/install
1	Remove underfloor paneling	ENGINE 276.8 in model 166, 292	AR61.30-P-1001GQ
		ENGINE 276.8 in model 251	AR61.30-P-1001RT
2	Remove left air filter housing (2)	For removal of the left oxygen sensor upstream of CAT (G3/3) and the left oxygen sensor downstream of CAT (G3/5).	AR09.10-P-1150GQC
3	Remove right air filter housing (1)	For removal of the right oxygen sensor upstream of CAT (G3 (/4) and the right oxygen sensor downstream of CAT (G3/6).	AR09.10-P-1150GQC
4	Remove windshield wiper system	ENGINE 276.8 in model 251 For removal of the left oxygen sensor upstream of CAT (G3/5) and the right oxygen sensor downstream of CAT (G3/6).	AR82.30-P-6400RT
5	Remove left rear heat shield	ENGINE 276.8 in model 251 For removal of the left oxygen sensor upstream of CAT (G3/3).	AR49.10-P-5500GQC
6	Remove right rear heat shield	ENGINE 276.8 in model 251 For removal of the right oxygen sensor upstream of CAT (G3/4).	AR49.10-P-5500GQC
7	Disconnect electrical connection for left oxygen sensor upstream of catalytic converter (G3/3x1) or electrical connection for the right oxygen sensor upstream of catalytic converter (G3/4x1) or electrical connection for the left oxygen sensor downstream of catalytic converter (G3/5x1) or electrical connection for the right oxygen sensor downstream of catalytic converter (G3/6x1)
8	Unclip electrical line of left oxygen sensor upstream of CAT (G3/3) or right oxygen sensor upstream of CAT (G3/4) or left oxygen sensor downstream of CAT (G3/5) or right oxygen sensor downstream of CAT (G3/6) from retaining clamps (3) and bracket
9	Remove catalytic converter	Only for removal of the left oxygen sensor downstream of CAT (G3/5).	AR49.10-P-5500GQC
10	Detach left oxygen sensor upstream of CAT (G3/3) or right oxygen sensor upstream of CAT (G3/4) or left oxygen sensor downstream of CAT (G3/5) or right oxygen sensor downstream of CAT (G3/6) from catalytic converter	: Coat thread with heat-resistant lubricant. Ensure correct routing of the lines. Oxygen sensor at catalytic converter	*BA14.00-P-1002-01A
		Paste, hot lubrication 1 kg, DBL 6879.20	*BR00.45-Z-1005-06A
		Box wrench bit	Fig 3
11	Install in the reverse order
12	Read out fault memory using the diagnostic system and clear if necessary
			AD00.00-P-2000-04A
	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
13	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