An exhaust line for a vehicle having an engine generating an exhaust and a device for supplying a reducing agent for use during treatment of the exhaust, said exhaust line comprising: a mixing housing having a continuous wall defining upstream and downstream ends (156, 158) with said wall further defining an opening extending between said upstream and downstream ends (156, 158) and a port for receiving the reducing agent from the device with said wall having first and second segments (153, 155); a first treatment block adjacent said downstream end of said mixing housing for treatment of the exhaust; a baffle (162, 362) disposed within said opening of said mixing housing; and a divider disposed between said wall and said baffle (162, 362) with said divider having first and second surfaces (220, 222), said first surface of said divider, said first segment of said wall, and said baffle (162, 362) defining a mixing chamber in fluid communication with said upstream end for receiving a portion of the exhaust, and said mixing chamber in fluid communication with said port for receiving the reducing agent; said second surface of said divider facing said second segment of said wall and defining a bypass chamber adjacent said mixing chamber with said divider defining a bypass inlet facing said upstream end for receiving another portion of the exhaust and a bypass outlet facing said downstream end for releasing the other portion of the exhaust with said divider operable to transfer heat from the other portion of the exhaust passing through said bypass chamber to the reducing agent inside said mixing chamber for effective treatment of the exhaust; wherein said divider further has a first lip adjacent said upstream end of said continuous wall and extending toward said second segment of said continuous wall with said first lip defining said bypass inlet at said upstream end for receiving the other portion of the exhaust. a mixing housing having a continuous wall defining upstream and downstream ends (156, 158) with said wall further defining an opening extending between said upstream and downstream ends (156, 158) and a port for receiving the reducing agent from the device with said wall having first and second segments (153, 155); a first treatment block adjacent said downstream end of said mixing housing for treatment of the exhaust; a baffle (162, 362) disposed within said opening of said mixing housing; and a divider disposed between said wall and said baffle (162, 362) with said divider having first and second surfaces (220, 222), said first surface of said divider, said first segment of said wall, and said baffle (162, 362) defining a mixing chamber in fluid communication with said upstream end for receiving a portion of the exhaust, and said mixing chamber in fluid communication with said port for receiving the reducing agent; said second surface of said divider facing said second segment of said wall and defining a bypass chamber adjacent said mixing chamber with said divider defining a bypass inlet facing said upstream end for receiving another portion of the exhaust and a bypass outlet facing said downstream end for releasing the other portion of the exhaust with said divider operable to transfer heat from the other portion of the exhaust passing through said bypass chamber to the reducing agent inside said mixing chamber for effective treatment of the exhaust; wherein said divider further has a first lip adjacent said upstream end of said continuous wall and extending toward said second segment of said continuous wall with said first lip defining said bypass inlet at said upstream end for receiving the other portion of the exhaust.