The exhaust purification device of an internal combustion engine comprises a catalyst 20 arranged in an exhaust passage and able to store oxygen; and an air-fuel ratio control device configured to control an air-fuel ratio of inflowing exhaust gas flowing into the catalyst. The air-fuel ratio control device is configured to perform a distribution forming control controlling the air-fuel ratio of the inflowing exhaust gas so that in the catalyst, a first region with an oxygen storage amount of equal to or greater than a predetermined value and a second region with an oxygen storage amount of less than the predetermined value are alternately formed along an axial direction of the catalyst. The total number of the first region and the second region formed by the distribution forming control is equal to or greater than three.

A method includes: initiating a low engine-out NOx (LEON) mode by controlling a component of a vehicle having an aftertreatment system to decrease an instantaneous engine-out NOx (EONOx) amount; comparing a temperature of the aftertreatment system during the LEON mode to a warm-operation threshold temperature; responsive to determining that the temperature of the aftertreatment system exceeds the warm-operation threshold temperature, disengaging the LEON mode; responsive to determining that the temperature of the aftertreatment system is below the warm-up operation threshold temperature, comparing information indicative of an operating status of the vehicle to a LEON exit threshold; and disengaging the LEON mode responsive to determining that the information indicative of the operating status of the vehicle during the LEON mode exceeds the LEON exit threshold.

A particle filter assembly for a motor vehicle includes a particle filter, an exhaust-gas-conducting line which opens into the particle filter, and a secondary air supply. The secondary air supply is formed separately from the exhaust-gas-conducting line and fresh air is suppliable to the particle filter via the secondary air supply.

Systems and methods for controlling a gasoline urea selective catalytic reductant catalyst are described. In one example, an observer is provided that corrects an estimate of an amount of NH.sub.3 that is stored in a SCR. The amount of NH.sub.3 that is stored in the SCR is a basis for generating additional NH.sub.3 or ceasing generation of NH.sub.3.

A hybrid vehicle includes a multi-cylinder engine, an exhaust gas control apparatus including a catalyst for removing exhaust gas from the multi-cylinder engine, an electric motor, and a control device configured to execute catalyst temperature increase control for stopping fuel supply to at least one cylinder and making an air-fuel ratio in each of remaining cylinders rich in a case where a temperature increase of a catalyst is requested during a load operation of the multi-cylinder engine, execute control such that an electric motor supplements insufficient drive power due to the execution of the catalyst temperature increase control, and change the air-fuel ratio in at least one of the remaining cylinders to a lean side after a temperature of the exhaust gas control apparatus becomes equal to or higher than a determination threshold value during the execution of the catalyst temperature increase control.

In one aspect, a system is provided and includes an engine including an exhaust valve, an exhaust manifold downstream of the exhaust valve and a muffler downstream of the exhaust manifold. The system also includes a catalyst positioned downstream of the exhaust valve.

When an amount of particulate matter (PM) collected by a gasoline particulate filter (GPF) reaches a predetermined amount, a central processing unit (CPU) executes a regeneration process for regenerating the GPF. That is, the CPU stops supply of fuel to any one of cylinders #1 to #4, while increasing an amount of fuel supplied to remaining cylinders. When a temperature of a three-way catalyst becomes equal to or higher than a first temperature, the CPU increases an injection amount to lower a temperature of exhaust gas. When the temperature of the three-way catalyst becomes equal to or higher than the first temperature during the execution of the regeneration process, the CPU does not increase the injection amount.

A provision of assemblies and methods for treating exhaust gases from combustion devices to reduce air contaminants in the exhaust gas. The exhaust from a combustion device is cooled, followed by passing the exhaust through first and second catalytic chambers with an oxygen enrichment means in between the catalytic chambers. The catalytic chambers comprise at least one catalyst that substantially reduces nitrogen oxides or carbon monoxide or both.

A nitrogen oxide purification system includes an exhaust line exhausting exhaust gas from a combustion chamber. A first nitrogen oxide purification device is mounted at an upstream side of the exhaust line to primarily purify nitrogen oxides (NOx) included in the exhaust gas, and a second nitrogen oxide purification device is mounted to a downstream side of the first nitrogen oxide purification device to secondarily purify the NOx. A second injector is disposed between the first nitrogen oxide purification device and the first injector to additionally inject fuel for controlling an air/fuel ratio of the exhaust gas.

There is provided an exhaust gas purification system including: a NOx storage-reduction catalyst that is provided in an exhaust system of an internal combustion engine to reduce and purify NOx in exhaust gas; a degree of deterioration estimation module 120 for estimating a degree of deterioration of the NOx storage-reduction catalyst; a regeneration control unit 100 for executing a regeneration process in which exhaust gas is enriched so as to restore a NOx storage capacity of the NOx storage-reduction catalyst; an interval setting module for setting a target interval from an end of the regeneration process to a start of the subsequent regeneration process by the regeneration control unit; and an interval target value correction module for correcting the target interval based on the degree of deterioration that is estimated by the degree of deterioration estimation module.