A heat exchanger may include a heat exchanger block and a diffusor connected thereto. At least one connecting pin may be integrally molded to a surface of the heat exchanger block. At least one passage opening, through which the at least one connecting pin may engage when the heat exchanger is mounted, may be arranged on the diffusor. The at least one connecting pin may have a widened head via which the diffusor may be secured to the heat exchanger block.

A device of a system for air ducting of an internal combustion engine in a motor vehicle with a turbocharger arranged between an exhaust gas line and an intake line. The device includes a high pressure flow pathway with a valve branching from the exhaust gas line between the internal combustion engine and a turbine side of the turbocharger, a low pressure flow pathway with a valve branching in the flow direction of the exhaust gas downstream from the turbine side of the turbocharger, and an exhaust gas heat exchanger. A first flow pathway with a valve and a second flow pathway with a valve merge into a mouth region with a third flow pathway. At least one section of the high pressure flow pathway, the low pressure flow pathway, the flow pathways, and the exhaust gas heat exchanger are integrated inside a housing formed as a continuous compact unit.

A device of a system for air ducting of an internal combustion engine in a motor vehicle with a turbocharger arranged between an exhaust gas line and an intake line. The device includes a high pressure flow pathway with a valve branching from the exhaust gas line between the internal combustion engine and a turbine side of the turbocharger, a low pressure flow pathway with a valve branching in the flow direction of the exhaust gas downstream from the turbine side of the turbocharger, and an exhaust gas heat exchanger. A first flow pathway with a valve and a second flow pathway with a valve merge into a mouth region with a third flow pathway. At least one section of the high pressure flow pathway, the low pressure flow pathway, the flow pathways, and the exhaust gas heat exchanger are integrated inside a housing formed as a continuous compact unit.

An exhaust gas recirculation system (12) comprises at least one exhaust gas recirculation line (13) which, in the direction of flow, branches off from an exhaust gas pipe (14) after an exhaust gas turbine (2) and/or a particulate filter (4) and/or a catalytic converter; in the direction of flow, opens out into a supply-air line (15) after a turbo-compressor (3) and comprises in its course at least one pump (11).

An exhaust gas recirculation system (12) comprises at least one exhaust gas recirculation line (13) which, in the direction of flow, branches off from an exhaust gas pipe (14) after an exhaust gas turbine (2) and/or a particulate filter (4) and/or a catalytic converter; in the direction of flow, opens out into a supply-air line (15) after a turbo-compressor (3) and comprises in its course at least one pump (11).

An exhaust gas recirculation apparatus including an engine; a suction line; an exhaust line; a post-processing unit which is disposed in the exhaust line to reduce hazardous substances contained in the exhaust gas; a first circulation line which guides a part of the exhaust gas, which is guided to the exhaust line, to the suction line; a second circulation line which guides a part of the exhaust gas, which is guided to a downstream side of the post-processing unit, to the suction line; and a bypass line which branches off from an upstream side of the second circulation line, and merges with a downstream side of the second circulation line, wherein ammonia slip, which is discharged from the post-processing unit, is prevented from being guided to the suction line.

An exhaust gas recirculation apparatus including an engine; a suction line; an exhaust line; a post-processing unit which is disposed in the exhaust line to reduce hazardous substances contained in the exhaust gas; a first circulation line which guides a part of the exhaust gas, which is guided to the exhaust line, to the suction line; a second circulation line which guides a part of the exhaust gas, which is guided to a downstream side of the post-processing unit, to the suction line; and a bypass line which branches off from an upstream side of the second circulation line, and merges with a downstream side of the second circulation line, wherein ammonia slip, which is discharged from the post-processing unit, is prevented from being guided to the suction line.

A method includes operating a spark ignition engine and flowing low pressure exhaust gas recirculation (EGR) from an exhaust to an inlet of the spark ignition engine. The method includes interpreting a parameter affecting an operation of the spark ignition engine, and determining a knock index value in response to the parameter. The method further includes reducing a likelihood of engine knock in response to the knock index value exceeding a knock threshold value.

A method includes operating a spark ignition engine and flowing low pressure exhaust gas recirculation (EGR) from an exhaust to an inlet of the spark ignition engine. The method includes interpreting a parameter affecting an operation of the spark ignition engine, and determining a knock index value in response to the parameter. The method further includes reducing a likelihood of engine knock in response to the knock index value exceeding a knock threshold value.

Methods and systems are provided for adjusting fuel injections provided to a cylinder when a fuel rail pressure deviation from a threshold pressure is detected. In one example, a method may include reducing a total number of pilot and/or main fuel injections provided to a cylinder in a given cylinder cycle in response to a reduction of pressure in a fuel rail. In this way, the threshold rail pressure may be maintained, reducing the likelihood the engine will be derated.