A modularly constructed exhaust gas treatment arrangement, comprising: - an entry interface for receiving exhaust gas 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 comprises the entry interface and the first mixing section, - a second module comprises the first deflection housing and the first catalytic converter arrangement of the first exhaust gas treatment section, wherein the second module is detachably connected to the first module, - a third module comprises the particle filter arrangement of the first exhaust gas treatment section, wherein the third module is detachably connected to the second module, - a fourth module comprises the second deflection housing, wherein the fourth module is detachably connected to the third module, - a fifth module comprises the second mixing section, the third deflection housing, and the second exhaust gas treatment section, wherein the fifth module is detachably connected to the fourth module. - an entry interface for receiving exhaust gas 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 comprises the entry interface and the first mixing section, - a second module comprises the first deflection housing and the first catalytic converter arrangement of the first exhaust gas treatment section, wherein the second module is detachably connected to the first module, - a third module comprises the particle filter arrangement of the first exhaust gas treatment section, wherein the third module is detachably connected to the second module, - a fourth module comprises the second deflection housing, wherein the fourth module is detachably connected to the third module, - a fifth module comprises the second mixing section, the third deflection housing, and the second exhaust gas treatment section, wherein the fifth module is detachably connected to the fourth module.