A number of variations may include a method including controlling low pressure EGR flow rates using air intake throttle with a variable swirl device or throttle valve, or using exhaust throttling.

A control device for controlling an engine based on an operating state of a vehicle is provided. The control device includes a processor configured to execute a basic target torque determining module for determining a basic target torque based on an operating state of the vehicle, a torque reduction amount determining module for determining a torque reduction amount based on a part of the operating state of the vehicle, a final target torque determining module for determining a final target torque based on the basic target torque and the torque reduction amount, an engine controlling module for controlling the engine to output the final target torque, and a torque change smoothing module for smoothing a chronological change of the final target torque corresponding to the torque reduction amount at a smaller smoothing degree than that of the chronological change of the final target torque corresponding to the basic target torque.

An engine device includes a main throttle valve disposed at a portion where an outlet of a supercharger and an inlet of an intercooler are coupled to each other, an exhaust bypass flow path configured to couple an outlet of an exhaust manifold to an exhaust outlet of the supercharger, an exhaust bypass valve disposed in the exhaust bypass flow path, an air supply bypass flow path configured to bypass a compressor of the supercharger, and an air supply bypass valve disposed in the air supply bypass flow path. Within a low load range of a load on the engine device, when the load is lower than a predetermined load, feedback control is performed on the main throttle valve, and when the load is higher than the predetermined load, map control based on a data table is performed on the main throttle valve.

A number of variations may include a method including controlling low pressure EGR flow rates using air intake throttle with a variable swirl device or throttle valve, or using exhaust throttling.

Methods and systems are provided for determining degradation of a particulate filter in an exhaust conduit. In one example, a method may include diverting exhaust gas to a secondary soot sensor assembly downstream of a first filter, comprising a filter and determining degradation based on time intervals between subsequent filter regenerations of the second filter in the secondary soot sensor assembly.