An internal combustion engine for a motor vehicle includes a drive shaft, an intake tract, an exhaust gas tract, an exhaust gas aftertreatment device disposed in the exhaust gas tract, a heating element disposed in the exhaust gas tract upstream of the exhaust gas aftertreatment device, an electrically assisted exhaust gas turbocharger, and a conduit element which is fluidically connected to the exhaust gas tract at a first connection point disposed downstream of the exhaust gas aftertreatment device and at a second connection point disposed upstream of the heating element.

An EHC line leakage diagnosis method can operate a heater of an oxygen detector when satisfying one or more conditions of an engine off time, a coolant temperature, and an outside air temperature by a diagnosis controller upon the key-on of the non-operation of an engine, and then, determine the normality or abnormality of a temperature drop using a change in a temperature value of a signal value and the temperature value detected by the oxygen detector after an air pump is driven, and then confirm the leakage of an exhaust line and a line on the rear end portion of an EHC valve of an air line using the number of times of the occurrence of the abnormality of the temperature drop, and can perform the failure diagnosis without generating the exhaust gas by not operating an engine.

A recycling loop configuration of an exhaust gas aftertreatment system decreases a level of system-out NO.sub.x emissions of an engine. An apparatus including the configuration has an exhaust gas recycling system having a closed gas recycling loop system configured to heat gas circulating within the loop, and a blower for circulating gas within the loop. A method for operating the engine includes preheating at least one aftertreatment component of an exhaust gas aftertreatment system of the engine by exposing the component to heated gas circulating in a closed gas recycling loop.

Methods and systems for improving NOx conversion efficiency of a selective catalytic reduction catalyst are described. In one example, an amount of NH.sub.3 stored in a SCR is adjusted after stopping an engine so that a desired amount of NH.sub.3 may be stored within the SCR when the engine is restarted.

An air intake and exhaust system for a marine engine having an intake manifold and an exhaust manifold includes an air compressor configured to compress ambient air into compressed air and a catalytic converter assembly configured to convert pollutants in an exhaust gas stream received from the exhaust manifold. The air compressor is configured to be fluidly coupled to the intake manifold of the engine for directing at least a first portion of the compressed air to the intake manifold of the engine. The air compressor is also selectively fluidly coupled to the catalytic converter assembly for selectively directing a second portion of the compressed air into the exhaust gas stream at a secondary air injection location at or upstream of the catalytic converter assembly.

The present invention relates to a method for controlling an internal combustion engine arrangement (100) connected to an exhaust gas aftertreatment system (200), wherein the method is arranged to control a gas heating device (122), as well as a gas feeding arrangement to direct a flow of intake air through the exhaust gas recirculation conduit (112) from the intake system to the exhaust system, the flow of intake air being directed through the gas heating device before the intake air enters the exhaust gas aftertreatment system, in response to determining a requested start of the internal combustion engine to heat the aftertreatment system before starting the engine.

A recycling loop configuration of an exhaust gas aftertreatment system decreases a level of system-out NO.sub.x emissions of an engine. An apparatus including the configuration has an exhaust gas recycling system having a closed gas recycling loop system configured to heat gas circulating within the loop, and a blower for circulating gas within the loop. A method for operating the engine includes preheating at least one aftertreatment component of an exhaust gas aftertreatment system of the engine by exposing the component to heated gas circulating in a closed gas recycling loop.

Methods and systems are provided for routing secondary air to engine an exhaust system during a cold-start condition to reduce tail pipe emissions. In one example, a method may include operating a pump of an evaporative leak check module (ELCM) in a positive pressure mode and routing pressurized air to the exhaust passage upstream of an exhaust catalyst via an air conduit housing a first valve.

An exhaust control system includes: a temperature control module configured to, in response to a shutdown of an engine, turn on an air pump that, when on, pumps air into an exhaust system of the engine upstream of a selective catalytic reduction (SCR) catalyst; a target module configured to, while the air pump is on and the engine is off in response to the shutdown, selectively determine a target rate of injection of a diesel exhaust fluid (DEF) by a DEF injector based on increasing a present amount of ammonia stored by the SCR catalyst to at least a predetermined amount of ammonia; and a DEF control module configured to, while the air pump is on and the engine is off in response to the shutdown, control injection of the DEF by the DEF injector upstream of the SCR catalyst based on the target rate.

A heat shield includes an outer jacket including a fluid inlet port and a fluid outlet port, and an inner jacket nested within the outer jacket and spaced apart therefrom to define a fluid passageway therebetween. The fluid passageway is in fluid communication with the fluid inlet port and the fluid outlet port for directing a cooling fluid from the fluid inlet port to the fluid outlet port through the fluid passageway. The inner jacket at least partially defines a main cavity configured to at least partially protect a turbocharger of the marine engine.