A method for the diagnosis of an air supply circuit supplying air to a burner of an exhaust gas after-treatment system for an exhaust system of an internal combustion engine, wherein the air supply circuit is provided with a pumping device housed along a first duct adjusted by a shut-off valve. The method entails housing a first pressure sensor along the first duct interposed between the pumping device and the burner; housing a second pressure sensor along a second duct out of the burner; acquiring the pressure signals detected by said first and second pressure sensors; and diagnosing faults and/or malfunctions in the air supply circuit depending on the pressure signals detected by said first and second pressure sensors.

An under-floor catalyst (33) includes a GPF (41) capable of trapping fine exhaust particles in exhaust gas, and a downstream-side catalyst (42) positioned on the downstream side of GPF (41). GPF (41) can be supplied with secondary air. When an internal combustion engine (10) is stopped during travel, the secondary air is supplied to GPF (41) in which the fine exhaust particles are accumulated. At this time, the temperature of GPF (41) is equal to or higher than a predetermined temperature. Thus, a deterioration in the exhaust gas purification performance of under-floor catalyst (33) at the time of the start of internal combustion engine (10) can be suppressed.

Methods and systems are provided for an exhaust gas arrangement. In one example, a system includes a lean-NO.sub.x trap arranged upstream of a selective-catalytic reduction device with an air supply device positioned to inject air therebetween, wherein the air supply device is activated in response to an exhaust gas being rich and an exhaust gas temperature exceeding a limit temperature.

An aftertreatment system structured to decompose constituents of an exhaust produced by an engine having a turbocharger including a turbine and a compressor coupled thereto, includes: a selective catalytic reduction system; an injector fluidly coupled to the selective catalytic reduction system and structured to selectively insert a reductant into the selective catalytic reduction system; an intake conduit fluidly coupled to a compressor outlet of the compressor and structured to deliver a compressed air from the compressor to the engine; and an air delivery line fluidly coupling the intake conduit to the injector, the air delivery line structured to deliver a portion of the compressed air to the injector.

The present disclosure relates generally to aftertreatment of exhaust gases in internal combustion engines. The teachings thereof may be embodied in a method for operating a secondary air system comprising: measuring an actual pressure downstream of a pump of the secondary air system; acquiring a dynamic pressure based on the actual pressure, characteristic of changes caused by dynamic operation of the engine; acquiring a basic pressure based on peripheral conditions of the secondary air system; calculating a model pressure based on the basic and the dynamic pressure; determining a capacity of the pump based on a ratio between the model pressure and the actual pressure; and adjusting operation of the secondary air system based on the capacity.

An ATS includes an SCR device and is connected to an internal combustion engine so as to receive an exhaust gas flow from at least one cylinder of the internal combustion engine when fuel is injected and combusted in such cylinder; an NH3 storage is increased in such SCR device after an engine shut off command has been detected, such that an increased NH3 storage is ready for a subsequent cold start of the internal combustion engine; the increase of NH3 storage is carried out by injecting a reducing agent in the ATS and by supplying an air flow towards the SCR device; such air flow flows through the cylinder after the fuel injection has been shut off.

The disclosure relates to a method and a device for diagnosing coking of a secondary air system of an internal combustion engine. The secondary air system has an intake air line for providing secondary air, a secondary air pump for compressing the secondary air, a secondary air valve for controlling the secondary air injection, a pressure sensor that is arranged in the secondary air system downstream of the secondary air pump and upstream of the secondary air valve, and an injection line for injecting the secondary air into an exhaust tract of the internal combustion engine.

Methods and systems are provided for controlling the temperature and ratio of gases within a gas mixing tank reservoir and selectively charging/discharging gases from the reservoir to one or both of an intake system or an exhaust system. In one example, a method (or system) may include storing exhaust gas and/or compressed intake air into a gas mixing reservoir, and increasing or decreasing flow of coolant to the reservoir based on engine operating conditions. The stored gases may be discharged to an intake system and/or an exhaust system based on requests from a controller, and coolant flow to the reservoir may be adjusted based on the composition of the gases stored within the reservoir.

A thermal management system for an aftertreatment system includes an air pump and a compressed air rail. The compressed air rail is fluidly connected with the air pump. The thermal management system further includes a first valve located between the compressed air rail and an exhaust outlet pathway. The first valve is configured to selective supply air to the aftertreatment system of the engine. The thermal management system further includes a heater located between the compressed air rail and the first valve. The heater is configured to heat the air before supplying air to the aftertreatment system of the engine.

A method for operating an engine includes selectively introducing air in an exhaust conduit upstream of a selective catalytic reduction system based on an exhaust gas temperature and a nitrous oxide conversion efficiency of the selective catalytic reduction system and changing at least one engine operating map for engine operation when the nitrous oxide conversion efficiency after introducing air is above a threshold nitrous oxide conversion efficiency.