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

ENGINE 272.920 in MODELS 203.052 /252 /752

ENGINE 272.940 in MODELS 203.054 /254, 209.354 /454

ENGINE 272.960 in MODELS 203.056 /256 /756, 209.356 /456

ENGINE 272.970 in MODELS 203.087 /287

ENGINE 272.941 in MODELS 203.092 /292

ENGINE 273 in MODEL 209

Fig 1: Identifying Heated O2 Sensor Components - Engine 272

Courtesy of MERCEDES-BENZ USA

	Remove/install
	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
	Notes on avoiding damage to electronic components due to electrostatic discharge		AH54.00-P-0001-01A
1	Turn key in ignition switch to position "0".
	Risk of death caused by vehicle slipping or toppling off the lifting platform.	Align vehicle between columns of lifting platform and position four support plates at lifting platform support points specified by vehicle manufacturer.	AS00.00-Z-0010-01A
2	Raise vehicle with lifting platform		AR00.60-P-1000P
3	Remove rear section of lower engine compartment paneling	Installation: Install engine compartment paneling only after the engine test run.	AR61.20-P-1105P
4	Unclip electrical connector and electrical feed line for corresponding O2 sensor out of retaining clamps on transmission
5.1	Remove heat shield for steering below left catalytic converter	Only when removing the left O2 sensor upstream of TWC (G3/3) on models 203.087 /092 /287 /292.
6	Disconnect electrical connector for corresponding O2 sensor
7.1	Remove complete exhaust system	Only when removing the left O2 sensor upstream of TWC (G3/3).	AR49.10-P-7000QB
8	Unscrew corresponding O2 sensor out of catalytic converter completely	Installation: Apply heat-resistant lubricant to thread of O2 sensor.
			*BA14.00-P-1002-01A
		Box wrench bit	Fig 2
		Socket	Fig 3
		Paste	*BR00.45-Z-1005-06A
9	Install in the reverse order
10	Read out fault memory	STAR DIAGNOSIS system	*WH58.30-Z-1048-13A
	Connect STAR DIAGNOSIS and read out fault memory		AD00.00-P-2000-04A
	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 running engine	Secure vehicle to prevent it from moving by itself. Wear closed and snug-fitting work clothes. Do not grasp hot or rotating parts.	AS00.00-Z-0005-01A
11	Conduct engine test run and check exhaust system for leaks