Remove/Install Exhaust Aftertreatment Unit - AR49.20-P-1500SA

Engine 256.9 in model 257 

with code 961 (Exhaust system with OPF, generation 2.0) 

Engine 256.9 in model 257 

with code 999 (Exhaust system with OPF, generation 3.0) 

Engine 256.9 in model 290 

with code 961 (Exhaust system with OPF, generation 2.0) 

Engine 256.9 in model 290 

with code 999 (Exhaust system with OPF, generation 3.0) 

Shown on model 290 with code 961 (Exhaust system with GPF generation 2.0) 

Courtesy of MERCEDES-BENZ USA

Shown on remove engine 256.9 with code 961 (Exhaust system with GPF generation 2.0) 

Shown on remove engine 256.9 with code 961 (Exhaust system with GPF generation 2.0) 

Courtesy of MERCEDES-BENZ USA

	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 burn injuries  , suffocation and poisoning when working on the exhaust system and the components connected to it. Risk of suffocation and risk of poisoning caused by inhalation of gaseous and solid components of the exhaust. Risk of poisoning  caused by skin contact with solid components of the exhaust.	Wear protective clothing and safety glasses. Use the extraction system. Move people out of the danger zone.	AS49.00-Z-0001-01A
	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
Notice	Information on preventing damage to electronic components due to electrostatic discharge		AH54.00-P-0001-01A
Notice	Notes on self-locking nuts and bolts		AH00.00-P-0001-01KOA
Notice	Notes on avoiding damage through contamination and foreign objects		AH00.00-P-5000-01A
	Note on calculation of tightening torque when using insertion or socket tools with various effective lengths		AH00.00-P-0015-01CW
	Remove/install
1	Remove upper Engine cover.	Do not install upper Engine cover until after the leak test.	AR01.10-P-2405MSA
2	Remove center and rear sections of lower Engine compartment lining.	Engine 256.9 in model 257 with code 961 (Exhaust system with OPF, generation 2.0) Engine 256.9 in model 257 with code 999 (Exhaust system with OPF, generation 3.0)	AR61.20-P-1105FR
		Engine 256.9 in model 290 with code 961 (Exhaust system with OPF, generation 2.0) Engine 256.9 in model 290 with code 999 (Exhaust system with OPF, generation 3.0)	AR61.20-P-1105FRX
		Only install center and rear lower rear Engine compartment lining again after leak test.
3	Remove exhaust system from the exhaust gas aftertreatment unit (1).		AR49.10-P-7142MSA
4	Remove gasoline particulate filter differential pressure sensor.	Engine 256.9 in model 257 with code 961 (Exhaust system with OPF, generation 2.0) Engine 256.9 in model 290 with code 961 (Exhaust system with OPF, generation 2.0)	AR49.20-P-3020SA
		Engine 256.9 in model 257 with code 999 (Exhaust system with OPF, generation 3.0) except code 961 (Exhaust system with OPF, generation 2.0) Engine 256.9 in model 290 with code 999 (Exhaust system with OPF, generation 3.0) except code 961 (Exhaust system with OPF, generation 2.0)	AR49.20-P-3020SAA
5	Remove gasoline particulate filter temperature sensor.		AR49.20-P-0200SA
6	Remove heat shield (2) between the coolant expansion reservoir and exhaust gas aftertreatment unit (1).	Nut, differential pressure sensor heat shield to heat shield	*BA49.10-P-1021-02P
7	Remove heat shield (3).	Observe retaining clamps.
		Nut/screw, heat shield to exhaust gas turbocharger/heat shield	*BA09.40-P-1004-02MRT
8	Remove heat shield (4).	Observe retaining clamps.
		Nut/screw, heat shield to exhaust gas turbocharger/heat shield	*BA09.40-P-1004-02MRT
9	Remove lower heat shield (5).	Observe retaining clamps.
		Nut/screw, heat shield to exhaust gas turbocharger/heat shield	*BA09.40-P-1004-02MRT
10	Release and disconnect electrical connector lambda sensor downstream of catalytic converter (G3/1x1) and expose electric line.
11	Release and disconnect electrical connector lambda sensor downstream of catalytic converter (G3/2x1) and expose electric line.
12	Remove screws (6, 7, 8, 9, 10).	Bolt, catalytic converter to bracket	*BA49.10-P-1005-02P
13	Remove clamp (11) between exhaust gas turbocharger (12) and exhaust gas aftertreatment unit (1).	Replace clamp (11).
		Profile clamp, exhaust system to exhaust gas turbocharger	*BA09.40-P-1001-02MRT
14	Remove exhaust gas aftertreatment unit (1).	Set of protective covers	Fig 3
15	Remove seal (13).	Replace seal (13).
		Set of protective covers	Fig 3
16	Remove lambda sensor downstream of catalytic converter (G3/1).	If exhaust gas aftertreatment unit (1) is to be replaced.	AR07.04-P-0085MSA
17	Remove oxygen sensor upstream of catalytic converter (G3/2).	If exhaust gas aftertreatment unit (1) is to be replaced.	AR07.04-P-0086MSA
18	Unscrew screw (14) and remove bracket (15).	If exhaust gas aftertreatment unit (1) is to be replaced.
		Screw, pressure line holder for differential pressure sensor to gasoline particulate filter	*BA49.10-P-1022-02P
19	Remove union nuts and differential pressure lines (16).	If exhaust gas aftertreatment unit (1) is to be replaced.
		Position the bracket (15) and the screw (14).
		Union nut, pressure line for differential pressure sensor to gasoline particulate filter	*BA49.10-P-1019-02P
		Box wrench bit	Fig 2
	Clean
20	Remove combustion and corrosion residue at connecting points.
	Check
21	Check exhaust gas aftertreatment unit (1) for damage.	If damage is present: ↓ Replace EATU (1).
22	Install in the reverse order.
	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
23	Perform an Engine test run; check the Engine for proper operation and the exhaust system for leaks.

Number	Designation		Engine 256
BA09.40-P-1001-02MRT	Profile clamp, exhaust system to exhaust gas turbocharger	Nm	17

Number	Designation		Engine 256
BA09.40-P-1004-02MRT	Nut/screw, heat shield to exhaust gas turbocharger/heat shield	Nm	8

Number	Designation		Model 257 with engine 256	Model 290 with engine 256
BA49.10-P-1005-02P	Bolt, catalytic converter to bracket	Nm	20	20

Number	Designation		Model 257 with engine 256	Model 290 with engine 256
BA49.10-P-1019-02P	Union nut, pressure line for differential pressure sensor to gasoline particulate filter	Nm	20	20

Number	Designation		Model 257 with engine 256	Model 290 with engine 256
BA49.10-P-1021-02P	Nut, differential pressure sensor heat shield to heat shield	Nm	8	8

Number	Designation		Model 257 with engine 256	Model 290 with engine 256
BA49.10-P-1022-02P	Screw, pressure line holder for differential pressure sensor to gasoline particulate filter	Nm	12	12