Remove/Install Catalytic Converter - AR49.20-P-0100MSA

Engine 256.9 in model 213, 238 

up to model year 2020 

Engine 256.9 in model 257, 290 

Shown on engine 256.9 without code 494 (USA version) 

Fig 1: Catalytic Converter Component Location - Engine 256.9 In Model 257 Without Code 494

Courtesy of MERCEDES-BENZ USA

Shown on engine 256.9 with code 494 (USA version) 

Fig 2: Catalytic Converter Component Location - Engine 256.9 In Model 257 With Code 494

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	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
	Remove/install
1	Remove upper engine cover.	Do not install upper engine cover until after the leak test.	AR01.10-P-2405MSA
2	Remove heat shield between the coolant expansion reservoir and catalytic converter (2).
3	Remove heat shield (9).	Engine 256.9 in model 213, 238, 257, 290 up to model year 2020 with code 494 (US version) Nut/screw, heat shield to exhaust gas turbocharger/heat shield	*BA09.40-P-1004-02MRT
4	Remove heat shield (3).	Nut/screw, heat shield to exhaust gas turbocharger/heat shield	*BA09.40-P-1004-02MRT
5	Release and disconnect electrical connectors (4) and unclip electric lines.
6	Remove exhaust system from catalytic converter (2).	Only install center and rear lower rear engine compartment paneling again after leak test.	AR49.10-P-7142MSA
7	Remove bolts (5).	Bolt, catalytic converter to bracket	*BA49.10-P-1005-02P
8	Remove bolts (7).	Bolt, catalytic converter to bracket	*BA49.10-P-1005-02P
9	Release upper screw of heat shield (8) and release heat shield (8) from clamp on heat shield (6).	The heat shield (8) remains in vehicle. M6X1	*BA00.10-P-1002-04A
10	Remove clamp between exhaust gas turbocharger (1) and catalytic converter (2).	Replace clamp. Replace seal. Profile clamp, exhaust system to exhaust gas turbocharger	*BA09.40-P-1001-02MRT
11	Remove catalytic converter (2).
12	Remove oxygen sensor upstream of catalytic converter (G3/2).	When replacing catalytic converter (2).	AR07.04-P-0086MSA
13	Remove oxygen sensor downstream of catalytic converter (G3/1).	When installing new catalytic converter (2).	AR07.04-P-0085MSA
	Clean
14	Remove combustion and corrosion residue at connecting points.
15	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
16	Perform an engine test run; check the engine for proper operation and the exhaust system for leaks.
17	Install center and rear lower engine compartment lining.	Engine 256.9 in model 213, 238 up to model year 2020	AR61.20-P-1105LWE
		Engine 256.9 in model 290 up to model year 2020	AR61.20-P-1105FRX
		Engine 256.9 in model 257 up to model year 2020	AR61.20-P-1105FR
18	Install upper engine cover.		AR01.10-P-2405MSA