Various embodiments include a method for operating an internal combustion engine with a three-way catalytic converter with lambda control, comprising: monitoring a NO. sensor for a lambda value downstream of the converter; setting a threshold value determining a lambda setpoint value upstream of the converter using the difference between the setpoint value of the electrical signal and the measured electrical signal if the signal is below the threshold; if above the threshold value, determining the lambda setpoint value upstream of the converter using the difference between a NH.sub.3 setpoint value of the NO. sensor and the measured NH.sub.3 signal of the NO. sensor; and if the measured NH.sub.3 concentration is higher than the NH.sub.3 setpoint value, increasing the lambda setpoint value upstream of the converter and, if the measured NH.sub.3 concentration is lower than the NH.sub.3 setpoint value, reducing the lambda setpoint value upstream of the converter.

A cylinder head defines an EGR crossover tube integrally formed in the cylinder head. The EGR crossover tube includes a first end fluidly coupled to an exhaust port of an engine. A second end is fluidly coupled to an intake port of the engine. A Venturi tube configuration is positioned between the first and second ends. A first sensor port extends through the cylinder head to the EGR crossover tube. The first sensor port is positioned at a restriction of the Venturi tube configuration. A second sensor port extends through the cylinder head to the EGR crossover tube. The second sensor port is positioned proximate the first end. A differential pressure sensor includes a first pressure sensor positioned in the first sensor port and a second pressure sensor positioned in the second sensor port.

An exhaust treatment system and method for the treatment of an exhaust stream from a combustion engine are provided. A first oxidation of compounds comprising one or more of nitrogen, carbon and hydrogen in the exhaust stream is carried out by a first oxidation catalyst. Further, a value (NO2_1/NOx_1)det for a ratio between a first amount of nitrogen dioxide and a first amount of nitrogen oxides leaving said first oxidation catalyst is determined. Active control of at least one parameter related to the combustion engine is carried out, based on the determined value, so that the ratio is impacted. A first additive is supplied into the exhaust stream, following which a first reduction of the first amount of nitrogen oxides is carried out through a catalytic reaction in a catalytic filter, which consists of a particulate filter with an at least partly catalytic coating with reduction characteristics. The catalytic filter is arranged for catching and oxidizing of soot particles, and to carry out the first reduction of the first amount of nitrogen oxides using the first additive.

An engine maintenance set can be generated via a computerized system using engine status data for an internal combustion engine. The generating can include operating on the engine status data using a set of computer-readable maintenance set generation rules, with the rules correlating an engine maintenance set with a triggering condition. The generating can include determining that the triggering condition is met, with the triggering condition including each of one or more triggering parameters being within one or more corresponding triggering value ranges. The triggering parameters can include at least one engine emission triggering parameter. The generating can further include producing the engine maintenance set using the maintenance set generation rules. The generated engine maintenance set can be issued, with the engine maintenance set including one or more commands to perform one or more maintenance operations to improve efficiency of the engine and/or one or more engine status notifications.

The present invention refers to a method for determining an amount of a substance in exhaust gas of an internal combustion engine, the method comprises the steps of: determining, for an effective condition of the engine, at least one operating parameter; determining, for a reference condition of the engine, a reference amount of the substance present in exhaust gas of the engine in the reference condition when being operated based on the determined operating parameter; determining an intake manifold temperature difference between the effective condition and the reference condition of the engine; and determining an effective amount of the substance in the exhaust gas of the engine in the effective condition in dependence on the determined reference amount of the substance and the determined intake manifold temperature difference.

An exhaust purification system includes a NOx-occlusion-reduction-type catalyst that occludes NOx in exhaust in a lean state and reduces and purifies the occluded NOx in exhaust in a rich state, and a NOx purge rich control unit that executes NOx purge of reducing and purifying the occluded NOx by putting the exhaust into the rich state by fuel injection control, where a catalyst temperature of the NOx-occlusion-reduction-type catalyst is equal to or higher than a catalyst temperature threshold value and a NOx occlusion amount of the NOx-occlusion-reduction-type catalyst is equal to or higher than an NOx occlusion amount threshold value, and executes the NOx purge when the catalyst temperature is lower than a catalyst temperature threshold value.

The invention relates to a method for detecting an unsealed location in a heat recovery system (5) of an internal combustion engine (1) of a motor vehicle. The heat recovery system (5) has at least one combustible working medium, a working medium circuit (6) with at least one EGR evaporator (7), a pump (8), and at least one expansion machine (9). The aim of the invention is to allow an early and reliable detection of leakages in the EGR evaporator (7) of a heat recovery system (5) in the simplest manner possible. This is achieved in that the internal combustion engine (1) is operated in the overrun mode, the oxygen concentration in the exhaust gas is ascertained and compared with a defined lower threshold, and if the lower threshold is undershot, a leakage in the EGR evaporator (7) is detected.

A system of controlling an engine provided with a dual continuously variable valve duration device may include an engine, an intake valve for selectively supplying air or a mixture of the air and fuel to the combustion chamber, an ignition switch to ignite a burner to burn the mixture, and an exhaust valve disposed in the combustion chamber to selectively discharge exhaust gas in the combustion chamber to an outside of the combustion chamber, the dual continuously variable valve duration device provided to adjust an intake duration of the intake valve and an exhaust duration of the exhaust valve, a warm-up catalytic converter including a three-way catalyst for purifying hydrocarbons, carbon monoxide, nitrogen oxides contained in the exhaust gas downstream of the engine, and a controller for adjusting an ignition timing, the intake duration and the exhaust duration of the ignition switch based on a driving condition of a vehicle.

A method for predictive open-loop and/or closed-loop control of an internal combustion engine with control variables pursuant to a model of the engine with characterizing variables and a control circuit for the control variables. The control variables are adjusted in an open-loop or closed-loop manner by measuring actual values and specifying target values of the characterizing variables and, optionally, depending on the boundary and/or environmental and/or ageing conditions. The characterizing variables are controlled pursuant to a model of the engine with the characterizing variables and a control circuit with the control variables. The controlling is part of a model-based predictive control, wherein the characterizing variables of the engine model are calculated and the control variables of the engine are adjusted in a predictively controlled manner. A model-based predictive non-linear controller is used for the controlling, which is constructed in a modular manner with a number of model-based predictive control modules.

A vehicle includes an engine, a fueling system, an exhaust assembly, and a controller. The fueling system controls fuel to the engine. The exhaust assembly releases combustion gas from the engine and includes at least one sensor and a catalytic converter. The controller is configured to control the engine, the fueling system and the exhaust assembly. The controller evaluates engine state and an output from the at least one sensor and commands a fueling strategy to control an oxygen storage capacity of the catalytic converter based on the engine state and output from the at least one sensor.