A method and system for monitoring an exhaust gas sensor coupled in an engine exhaust is provided. In one example, the method adjusts an estimate of an exhaust gas oxygen sensor delay time based on a fuel injection ramping time. The fuel injection ramping time compensates for fuel that is injected to the engine while the engine enters or exits a fuel cut-off mode.

An internal combustion engine, with an engine regulating device and an exhaust gas aftertreatment device with an SCR catalytic converter for the reduction of at least one NO.sub.x component, and with a catalytic converter regulating device, wherein the engine regulating device is prescribed a target value for an NO.sub.x mean value of the NO.sub.x component of the exhaust gases, which mean value results at an outlet point of the exhaust gas aftertreatment device in relation to a predefinable time period, and the engine regulating device is configured at least in one operating mode to continuously calculate an NO.sub.x reference value for the catalytic converter regulating device with consideration of No.sub.x components which have already been emitted and the predefined target value, which reference value is selected in such a way that the predefined target value results at the outlet point of the exhaust gas aftertreatment device at the end of the predefinable time period when the calculated NO.sub.x reference value of the catalytic converter regulating device is fed as NO.sub.x setpoint value to the regulating means.

An exhaust catalyst management apparatus to be applied to a vehicle includes a differential pressure sensor and one or more processors. The differential pressure sensor detects an accumulation state of an exhaust-containing substance in a catalyst device. The one or more processors are coupled to the differential pressure sensor and a vehicle outside sensor. The one or more processors determine whether or not travel environment is suited to carrying out an output control for removal, based on a result of the detection of surroundings of the vehicle by a vehicle outside sensor. Upon determining that the travel environment is suited to carrying out the output control for removal, the one or more processors carry out the output control for removal, while the vehicle is traveling, in accordance with a result of the determination of the accumulation state of the exhaust-containing substance in the catalyst device.

A method for reducing deposits related to a reduction agent (RA) in a portion of an exhaust aftertreatment system (EAS) of an internal combustion engine (ICE) and comprising an injector for injecting the RA into said EAS, said portion located downstream of said injector, as seen in an intended direction of flow of exhaust gas in said EAS, said method comprising: identifying for said ICE, a future operating sequence (FOS) comprising a first temporal portion (t.sub.1) and a second temporal portion (t.sub.2) subsequent to t.sub.1, confirming that said FOS is suitable for reducing deposits and that said ICE operates in accordance with said FOS, in response to said confirming being affirmative, injecting a first dosage (d.sub.1) of RA into said EAS during at least a part of said t.sub.1 and injecting a second dosage (d.sub.2) of RA smaller than d.sub.1 into said EAS during at least a part of t.sub.2.

A control device is configured to direct an opening degree of a throttle valve disposed in an intake passage or an exhaust passage of an engine including a DOC disposed in the exhaust passage and a DPF disposed downstream of the DOC in the exhaust passage. The control device includes: a hysteresis occurring condition determination unit configured to determine whether a hysteresis occurring condition (predetermined time elapses after instructed opening degree of throttle valve becomes equal to or smaller than predetermined opening degree and/or predetermined time elapses after engine output becomes equal to or smaller than predetermined output) is met; and a hysteresis elimination execution unit configured to cause, if it is determined that the hysteresis occurring condition is met, the throttle valve to execute hysteresis elimination that involves temporarily increasing the opening degree of the throttle valve from the instructed opening degree and then returning it to the instructed opening degree.

A method for operating a petrol engine, in which air is introduced into an exhaust tract through which exhaust gas from the petrol engine can flow, bypassing the petrol engine, includes introducing the air into the exhaust tract at a point arranged downstream of a first three-way catalytic converter arranged in the exhaust tract and upstream of a second three-way catalytic converter arranged in the exhaust tract downstream of the first three-way catalytic converter, while the petrol engine is operated with a sub-stoichiometric combustion air ratio, where a desulphurization of the second three-way catalytic converter is effected.

An internal combustion engine (1), with an engine regulating device (3) and an exhaust gas aftertreatment device (16) with an SCR catalytic converter (4) for the reduction of at least one NO.sub.x component, and with a catalytic converter regulating device (6), wherein the engine regulating device (3) is prescribed a target value for an NO.sub.x mean value of the NO.sub.x component of the exhaust gases, which mean value results at an outlet point (7) of the exhaust gas aftertreatment device (16) in relation to a predefinable time period, and the engine regulating device (3) is configured at least in one operating mode to continuously calculate an NO.sub.x reference value for the catalytic converter regulating device (6) with consideration of No.sub.x components which have already been emitted and the predefined target value, which reference value is selected in such a way that the predefined target value results at the outlet point of the exhaust gas aftertreatment device (16) at the end of the predefinable time period when the calculated NO.sub.x reference value of the catalytic converter regulating device (6) is fed as NO.sub.x setpoint value to the regulating means.

A method for the onboard diagnosis in a vehicle having a catalytic convertor and a lambda-controlled internal combustion engine in the running operation of the vehicle, includes determining the currently maximum possible oxygen storage capacity of the catalytic convertor as well as a measured temporal duration between the lean spike of the pre-catalyst lambda probe and the post-catalyst lambda probe takes place by means of an OSC diagnosis. The method also includes determining a theoretical residual oxygen content and determining a theoretical temporal duration. When the quotient between the measured temporal duration (Δt) and the theoretical temporal duration (Δt.sub.theo) lies within a predefined range delimited by a first and a second threshold value (SW1; SW2), thus: $\mathrm{SW}1\le \frac{\Delta t}{\Delta t_{\mathrm{theo}}}\le \mathrm{SW}2,$
it is determined that the pre-catalyst lambda probe and the post-catalyst lambda probe operate without flaw.

A prediction device that predicts time for a reducing agent accommodated in a container mounted on a work vehicle to freeze includes a remaining amount information acquisition unit configured to acquire remaining amount information indicating a remaining amount of the reducing agent in the container, a wall surface temperature acquisition unit configured to acquire a detection result of a wall surface temperature of the container, a reducing agent temperature acquisition unit configured to acquire a detection result of a temperature of the reducing agent, and a time calculation unit configured to calculate the time for the reducing agent to freeze based on the wall surface temperature, the reducing agent temperature, and the remaining amount information.

A reuse evaluation system is a system that performs an evaluation to reuse a catalyst in a state where the catalyst that purifies an exhaust gas of an engine of a vehicle 1 is mounted on the vehicle. The reuse evaluation system includes a deterioration estimator that estimates a degree of deterioration of the catalyst based on an operating state of the vehicle, a reuse setting unit that sets a range of the degree of deterioration of the catalyst as a reuse range of the catalyst according to a usage of reuse of the catalyst, and a reuse determining unit that determines that the catalyst is reusable in the reuse usages when the degree of deterioration of the catalyst estimated by the deterioration estimator is within the reuse range set by the reuse setting unit.