Remove/Install Oxygen Sensors - AR07.04-P-0021MLJ

ENGINE 157, 278 in MODEL 166

ENGINE 157, 278 in MODEL 292

Shown on left catalytic converter

Shown on the right catalytic converter

	Remove/install
1	Remove underfloor paneling		AR61.30-P-1001GQ
2	Unclip electrical connection for left oxygen sensor upstream of catalytic converter (5) and electrical connection for left oxygen sensor on catalytic converter (7) from bracket on transmission (5)
3	Detach left oxygen sensor upstream of catalytic converter (1) and left oxygen sensor upstream of catalytic converter (3)	Coat thread with heat-resistant lubricant. Ensure correct routing of lines for the oxygen sensors (1, 3). Oxygen sensor downstream of catalytic converter	*BA14.00-P-1004-01A
		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 1
4	Unclip electrical connection for right oxygen sensor upstream of catalytic converter (6) and electrical connection for right oxygen sensor on catalytic converter (8) from bracket on transmission (5)
5	Detach right oxygen sensor upstream of catalytic converter (2) and right oxygen sensor on catalytic converter (4)	Coat thread with heat-resistant lubricant. Ensure correct routing of lines for the oxygen sensors (2, 4). Oxygen sensor downstream of catalytic converter	*BA14.00-P-1004-01A
		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 1
6	Install in the reverse order
7	Read out fault memory using the diagnostic system and clear if necessary
			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
8	Carry out an engine test run and check exhaust system for leaktightness

OXYGEN SENSOR

Number	Designation		Engine 157, 278
BA14.00-P-1004-01A	Oxygen sensor downstream of catalytic converter	Nm	50

OXYGEN SENSOR

Number	Designation		Engine 157, 278
BA14.00-P-1005-01A	Oxygen sensor upstream of catalytic converter	Nm	50

Fig 1: Identifying Box Wrench Bit (000 589 71 03 00)

Courtesy of MERCEDES-BENZ USA

REPAIR MATERIALS

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