Front exhaust pipe (B258i)
 
  
 
 
  
   
    
     |  | Front exhaust pipe (B258i) | 
   
  
  
  
  
   
  
  
  
   
    
     
      | 1. | Disconnect the oxygen sensors' cables, undo the cable clamps and the clip and lift up the car. 
 
 
         
          
           | Important |  
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             Do not twist the cables. The oxygen sensors are sensitive to blows and impacts and must be handle with care.
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      | 2. | Remove the oxygen sensors, one for each cylinder bank. 
 
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      | 3. | Undo the joint between the front exhaust pipe and the catalytic converter. 
 
   
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      | 4. | Unscrew the front exhaust pipe from the exhaust manifolds. 
 
 
         
          
           | Important |  
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             There are seals between the exhaust manifold and the front exhaust pipe.
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      | 2. | Feed in the front exhaust pipe and bolt it to the exhaust manifold. Use new gaskets. 
 Turning torque 40 Nm (30 lbf ft).
 
 
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      | 3. | Bolt together the joint under the car. 
 Tightening torque 20 Nm (15 lbf ft).
 
 
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      | 4. | Refit the oxygen sensors. Lubricate the threads with Molycote 1000 prior to fitting. 
 
   Tightening torque 55 Nm (41 lbf ft).
 
 
 
         
          
           | Important |  
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             The oxygen sensors are sensitive to blows and impacts and must be handled with care. It is important that the connection between the oxygen sensors and the nipples is gas-tight.
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      | 5. | Lower the car and reconnect the oxygen sensors' cables. Refit cable clamps and clips. 
 
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