A modularly constructed exhaust gas treatment arrangement, comprising: - an entry interface for receiving exhaust gas (A) in the exhaust gas treatment arrangement , - a first mixing section , - a first exhaust gas treatment section having a first catalytic converter arrangement and a particle filter arrangement , - a second mixing section , - a second exhaust gas treatment section having a second catalytic converter arrangement , - a first deflection housing , which connects an exit area of the first mixing section to an entry area of the first exhaust gas treatment section , - a second deflection housing , which connects an exit area of the first exhaust gas treatment section to an entry area of the second mixing section , - a third deflection housing , which connects an exit area of the second mixing section to an entry area of the second exhaust gas treatment section , characterized in that : - a first module (M1) comprises the entry interface and the first mixing section , - a second module (M2) comprises the first deflection housing and the first catalytic converter arrangement of the first exhaust gas treatment section , wherein the second module (M2) is detachably connected to the first module (M1), - a third module (M3) comprises the particle filter arrangement of the first exhaust gas treatment section , wherein the third module (M3) is detachably connected to the second module (M2), - a fourth module (M4) comprises the second deflection housing , wherein the fourth module (M4) is detachably connected to the third module (M3), - a fifth module (M5) comprises the second mixing section , the third deflection housing , and the second exhaust gas treatment section , wherein the fifth module (M5) is detachably connected to the fourth module (M4). - an entry interface for receiving exhaust gas (A) in the exhaust gas treatment arrangement , - a first mixing section , - a first exhaust gas treatment section having a first catalytic converter arrangement and a particle filter arrangement , - a second mixing section , - a second exhaust gas treatment section having a second catalytic converter arrangement , - a first deflection housing , which connects an exit area of the first mixing section to an entry area of the first exhaust gas treatment section , - a second deflection housing , which connects an exit area of the first exhaust gas treatment section to an entry area of the second mixing section , - a third deflection housing , which connects an exit area of the second mixing section to an entry area of the second exhaust gas treatment section , - a first module (M1) comprises the entry interface and the first mixing section , - a second module (M2) comprises the first deflection housing and the first catalytic converter arrangement of the first exhaust gas treatment section , wherein the second module (M2) is detachably connected to the first module (M1), - a third module (M3) comprises the particle filter arrangement of the first exhaust gas treatment section , wherein the third module (M3) is detachably connected to the second module (M2), - a fourth module (M4) comprises the second deflection housing , wherein the fourth module (M4) is detachably connected to the third module (M3), - a fifth module (M5) comprises the second mixing section , the third deflection housing , and the second exhaust gas treatment section , wherein the fifth module (M5) is detachably connected to the fourth module (M4). <EOS>