A method for detecting catalyst deterioration in a vehicle includes executing a fuel-cut mode of an engine of the vehicle according to a operating state of the vehicle; calculating an oxygen storage capacity (OSC) of a catalyst using an oxygen sensor during the executing of the fuel-cut mode of the engine; and calculating catalyst deterioration based on the calculated OSC.

An apparatus for exhaust gas purification comprises a filter function. The apparatus includes a gas-permeable substrate which forms a wall-flow filter that forms channels. The channels are sealed at least at one end and exhaust gas is flowable through the channels and gas-permeable channel walls of the channels formed from the substrate. A surface of the substrate is provided with an oxygen-storing coating. The mass of an oxygen-storing material coated on the surface of the substrate on an outflow side is higher than the mass of the oxygen-storing material coated on the surface of the substrate on an inflow side.

An oxygen storage material comprises a LaCoAl-based composite oxide containing lanthanum, cobalt and aluminum. The LaCoAl-based composite oxide is in a form in which at least part of the aluminum is solid-dissolved in a LaCo composite oxide having a perovskite structure, and has a composition expressed by the following chemical formula (1):

LaCo.sub.yAl.sub.xO.sub.(1)

where x and y are numbers satisfying conditions of 0<x <1 and 0<y<1, where x+y=0.5 to 1.5, and is a number of 1.5 to 4.5.

A catalyst oxygen purge control method may include a catalyst oxygen purge control method during a cold engine period of a catalyst oxygen purge control apparatus which includes a three way catalytic converter through which an exhaust gas combusted when air and fuel are mixed in a combustion chamber is exhausted and the exhaust gas passes, wherein the method includes determining whether a fuel cut condition of an injector which injects the fuel to the combustion chamber is satisfied, performing fuel cut of the injector when the fuel cut condition is satisfied, measuring an oxygen storage capacity of the three way catalyst, and adjusting an oxygen purge time based on the measured oxygen storage capacity.

An exhaust gas purification apparatus for an internal combustion engine includes a filter supporting the catalyst with an oxygen storage capacity, an air fuel ratio sensor to detect an air fuel ratio of exhaust gas at the downstream side of the filter, and a controller configured to change an air fuel ratio of exhaust gas flowing into the filter, to estimate an amount of particulate matter deposited in an interior of a partition wall of the filter, estimate a maximum storable oxygen amount of the catalyst from a change of the air fuel ratio of exhaust gas obtained by the air fuel ratio sensor at the time when the air fuel ratio of exhaust gas is changed by the controller, and correct the maximum storable oxygen amount of the catalyst based on the amount of particulate matter deposited in the interior of the partition wall of the filter.

An exhaust gas purification apparatus for an internal combustion engine includes a particulate filter, an air fuel ratio sensor to detect an air fuel ratio of exhaust gas at the downstream side of the filter, and a controller configured to: change an air fuel ratio, determine whether an amount of particulate matter (PM) deposited in an interior of a partition wall of the filter is equal to or smaller than a predetermined amount, and estimate a maximum storable oxygen amount of the catalyst from a change of the air fuel ratio of exhaust gas at the time when the air fuel ratio of the exhaust gas is changed, in cases where the amount of PM deposited in the interior of the partition wall of the filter is equal to or smaller than the predetermined amount.

The present disclosure provides a method for operating an exhaust gas aftertreatment device for cleaning an exhaust gas flow of a motor vehicle with an internal combustion engine operated in normal mode with oxygen surplus. An oxygen store arranged downstream of an NOx storage catalyst of the exhaust gas aftertreatment device receives oxygen in normal mode, and during a regeneration mode emits oxygen for converting breakthrough hydrocarbons and/or carbon monoxide. The oxygen store is assigned to a particulate filter and/or an oxidation catalyst of the exhaust gas aftertreatment device. The particulate filter and/or the oxidation catalyst is arranged downstream of the NOx storage catalyst.

Methods and systems are provided for an exhaust aftertreatment arrangement. In one example, a system includes a LNT upstream of an SCR with an oxygen storage component arranged therebetween, and where a rich operation of an engine is limited based on an oxygen load of the oxygen storage component when an exhaust gas temperature is higher than a limit temperature.

An exhaust gas control apparatus includes a first catalyst, a filter, and an electronic control unit. The electronic control unit is configured to alternately execute lean control and rich control multiple times. The lean control is control for, over a period longer than a period from when a target air-fuel ratio is set to a predetermined lean air-fuel ratio until an air-fuel ratio of exhaust gas flowing out from the first catalyst becomes greater than the stoichiometric air-fuel ratio, setting the target air-fuel ratio to the predetermined lean air-fuel ratio. The rich control is control for, over a period longer than a period from when the target air-fuel ratio is set to a predetermined rich air-fuel ratio until the air-fuel ratio of exhaust gas flowing out from the first catalyst becomes smaller than the stoichiometric air-fuel ratio, setting the target air-fuel ratio to the predetermined rich air-fuel ratio.

Technical solutions are described for limiting exposure of components of an emissions control system to rich exhaust conditions. An example an emissions control system includes an oxygen storage component; and a controller that limits exposure of the oxygen storage component to rich exhaust conditions. The limiting includes determining an air-to-fuel equivalence ratio in exhaust gas in response to an engine receiving a request to generate torque, the request including a displacement of a pedal; determining an amount of oxygen in the exhaust gas based on the air-to-fuel equivalence ratio; determining an oxygen level stored by the oxygen storage component; and if the oxygen level is above a predetermined threshold, lowering a torque generation rate of the engine, which specifies amount of torque generated per unit displacement of the pedal.