Provided is an engine system including: a bypass pipe (bypass flow passage) connecting an upstream side and a downstream side of the turbine on an exhaust flow passage; a bypass valve configured to open and close the bypass flow passage; and a catalytic activation controller configured to control the bypass valve and a compression ratio of a combustion chamber.

An engine includes: an engine main body including a plurality of cylinders; a plurality of exhaust pipes connected to exhaust sides of the plurality of cylinders; a plurality of throttle valves positioned on intake sides of the plurality of cylinders; a catalyst device connected to the plurality of exhaust pipes; and a controller configured to control opening and/or closing operations of the plurality of throttle valves. One of the exhaust pipes is formed shorter than other exhaust pipe. And the controller opens one of the throttle valves upstream of the one of the exhaust pipes at a higher speed or a larger opening degree than other throttle valve upstream of the other exhaust pipe when the engine is started.

A method for operating an internal combustion engine with an exhaust gas aftertreatment device has a control system that determines a vector field of corresponding engine operating points (n.sub.Eng.sup.i, M.sub.Eng.sup.i) depending on a predetermined reducing agent-fuel consumption weighting q.sub.FD to be maintained during the operation of the internal combustion engine in order to derive a specific DEF-fuel consumption BSFC.sup.i for each of the engine operating points (n.sub.Eng.sup.i, M.sub.Eng.sup.i). The control system selects the element i.sup.Set from the identified vector field to which a minimum specific DEF-fuel consumption BSFC.sup.Set corresponds as the setpoint engine operating point (n.sub.Eng.sup.Set, M.sub.Eng.sup.Set), wherein the control system specifies a setpoint engine speed n.sub.Eng.sup.Set according to the selected element i.sup.Set and specifies therefrom a setpoint gear ratio r.sup.Set, taking into account a current gearbox output speed n.sub.out.

An exhaust gas aftertreatment system for an internal combustion engine has an exhaust system that can be connected to an outlet of the internal combustion engine. A three-way catalytic converter that is situated close to the engine and, downstream from the three-way catalytic converter that is situated close to the engine, a second catalytic converter and a particle reduction device are arranged in the direction in which an exhaust gas of the internal combustion engine flows through an exhaust gas channel of the exhaust system. A fuel injector is arranged on the exhaust gas channel so as to inject fuel downstream from the three-way catalytic converter that is situated close to the engine and upstream from the second catalytic converter, and the exhaust system comprises a secondary air system with which secondary air can be blown into the exhaust gas channel downstream from the three-way catalytic converter that is situated close to the engine and upstream from the second catalytic converter.

A catalyst deterioration diagnosis method is a method for a system. The system includes a gas sensor having ammonia interference property that measures an air-fuel ratio and nitrogen oxide concentration of an exhaust gas that has passed through a catalyst. Monitoring of temporary increase of nitrogen oxide concentration to be detected by the gas sensor is started, and thereby a temporarily increased amount of the nitrogen oxide concentration is acquired. The monitoring is started when a fuel injection device restarts fuel injection after a fuel cut in a case where an air-fuel ratio most recently obtained by the gas sensor is larger than a predetermined threshold air-fuel ratio. The predetermined threshold air-fuel ratio is larger than a stoichiometric air-fuel ratio. Whether or not the temporarily increased amount is larger than a threshold amount is determined.

A vehicle comprising an internal combustion engine, an electrical heated type catalyst device provided in an exhaust passage of the internal combustion engine and including a conductive substrate generating heat upon energization and a catalyst heated through the conductive substrate, and a control device, the control device comprising an internal moisture calculating part calculating an amount of internal moisture comprised of an amount of moisture present at an inside of the catalyst device and an engine output control part controlling the output of the internal combustion engine based on a required vehicle output and the amount of internal moisture. The engine output control part is configured so that if moisture is present at the inside of the catalyst device, it restricts the output of the internal combustion engine to a lower output when the internal moisture is large compared to when it is small.

An exhaust gas catalyst system that includes at least one exhaust canister including an inlet separated from an outlet with catalytic components positioned between the inlet and outlet. The at least one exhaust canister receives a flow of exhaust gas. The at least one exhaust canister includes a pair of concentric passages formed therein including a central passage and an outer passage. A split flap valve is positioned in the inlet. An actuator is coupled to the split flap valve. A control unit is operably connected to the actuator and selectively moves the split flap valve closing one of the concentric passages and locally heating a portion of the catalytic components.

Systems and apparatuses include an a system including an engine out sensor, an exhaust sensor, and one or more processing circuits comprising one or more memory devices coupled to one or more processors. The one or more memory devices are configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to receive the engine out sensor information from the engine out sensor, receive the exhaust information from the exhaust sensor, determine the aftertreatment system characteristic based on the exhaust information, compare the aftertreatment system characteristic to an exhaust condition, determine an acceptable input value when the aftertreatment system characteristic meets the exhaust condition, and control at least one of a fuel system actuator and an air handling actuator to achieve the acceptable input value.

Methods and/or systems for operating an exhaust-gas aftertreatment system of an internal combustion engine include: setting the internal combustion engine to a diagnostic operating mode with relevant diagnostic operating parameters of the internal combustion engine are set to correspond with diagnostic default values; inducing a targeted, defined NH.sub.3 and/or NO.sub.x concentration change upstream of the filter; measuring the NH.sub.3 and/or NO.sub.x concentration change downstream of the filter; providing a correlating concentration comparison value; evaluating the concentration change on the basis of the respective concentration comparison value and predefined limit values; and diagnosing the SCR particle filter as defective if the evaluation yields that the concentration comparison value has overshot a predefined limit value.

An exhaust gas catalyst system that includes at least one exhaust canister including an inlet separated from an outlet with catalytic components positioned between the inlet and outlet. The at least one exhaust canister receives a flow of exhaust gas. The at least one exhaust canister includes a pair of concentric passages formed therein including a central passage and an outer passage. A split flap valve is positioned in the inlet. An actuator is coupled to the split flap valve. A control unit is operably connected to the actuator and selectively moves the split flap valve closing one of the concentric passages and locally heating a portion of the catalytic components.