An EHC line leakage diagnosis method can operate a heater of an oxygen detector when satisfying one or more conditions of an engine off time, a coolant temperature, and an outside air temperature by a diagnosis controller upon the key-on of the non-operation of an engine, and then, determine the normality or abnormality of a temperature drop using a change in a temperature value of a signal value and the temperature value detected by the oxygen detector after an air pump is driven, and then confirm the leakage of an exhaust line and a line on the rear end portion of an EHC valve of an air line using the number of times of the occurrence of the abnormality of the temperature drop, and can perform the failure diagnosis without generating the exhaust gas by not operating an engine.

An aftertreatment system includes an exhaust reductant tank configured to store an exhaust reductant. A filter is fluidically coupled to the exhaust reductant tank. The aftertreatment system includes a hydrocarbon detection device configured to indicate the presence of a hydrocarbon in the exhaust reductant. A catalyst is included in the system and configured to treat the exhaust reductant flowing through the system. The hydrocarbon detection device can include a hydrophobic paper, and can be disposed in the filter.

A method for checking the operability of a secondary-air system of an internal combustion engine includes measuring a first pressure between a first secondary-air pump and a first master secondary-air valve as well as a second master secondary-air valve, measuring a second pressure between a second secondary-air pump and a first slave secondary-air valve and a second slave secondary-air valve, controlling the first master secondary-air valve and the first slave secondary-air valve together, and controlling the second master secondary-air valve and the second slave secondary-air valve together. A secondary-air system includes a first control and a second control, wherein a first master secondary-air valve and a first slave secondary-air valve are controllable together by the first control and wherein a second master secondary-air valve and a second slave secondary-air valve are controllable together by the second control.

An exhaust gas aftertreatment system for an internal combustion engine, which comprises an exhaust system which can be connected to the outlet of an internal combustion engine. A catalytic converter close to the engine and a second catalytic converter arranged downstream of the catalytic converter in an underbody of a motor vehicle are provided in the flow direction of an exhaust gas from the internal combustion engine flowing through an exhaust gas duct of the exhaust system. An inlet point for secondary air, an exhaust gas burner, and a fuel injector for introducing fuel into the exhaust gas duct are arranged downstream of the catalytic converter close to the engine and upstream of the second catalytic converter. According to the invention, the exhaust gas burner is activated immediately after the internal combustion engine is started in order to heat the second catalytic converter to its light-off temperature. Once the second catalytic converter has reached its light-off temperature, secondary air and fuel are additionally introduced into the exhaust gas duct and are exothermically reacted on the second catalytic converter in order to support the heating of the second catalytic converter.

The present disclosure relates to internal combustion engines. The teachings thereof may include monitoring a secondary air system with which secondary air is introduced into exhaust of the internal combustion engine wherein individual cylinders of the internal combustion engine are associated with one of at least two cylinder banks and a separate exhaust duct is associated with each cylinder bank. The methods may include delivering secondary air with a compression arrangement via a common secondary air line divided into a number of individual secondary air sublines corresponding to the number of exhaust ducts at a branching point downstream of the compression arrangement; controlling the secondary air to simultaneously enable or inhibit the flow to the individual secondary air sublines; detecting values for the pressure downstream of the compression arrangement and upstream of the branching point; detecting pulsations of a pressure in each cylinder bank when the compression arrangement is activated and the throughflow control arrangement set into the open state; summing the pulsations; comparing each of summed-up values with threshold values; and if the respective threshold value is exceeded, identifying a fault in the throughflow control arrangement.

A flow manifold system for injecting a first gas into a second gas, such as, for example, a system for injecting ammonia gas into the exhaust gas of an internal combustion engine. The first gas may be supplied to the system by one or more cartridges. The system may also include a control valve that is configured to control the delivery of the first gas to the least one critical flow orifice. The critical flow orifice is configured to allow for a relatively constant volumetric flow of the first gas through the critical flow orifice when the first gas attains a critical flow. Such critical flow may allow for an accurate estimation of the flow of the first gas through the critical orifice, and subsequently to the second gas, without the use of a flow sensor.

A process for detecting reductant deposits includes accessing data indicative of signal output from a radiofrequency sensor positioned proximate a decomposition reactor tube; comparing the data indicative of signal output from the radiofrequency sensor to a deposit formation threshold; and activating a deposit mitigation process responsive to the data indicative of signal output from the radiofrequency sensor exceeding the deposit formation 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.

A diesel engine high pressure SCR ventilation and voltage stabilisation system, comprising an SCR reactor (10), an air intake pipeline (20) and an exhaust pipeline (30) respectively connected to an air inlet and an exhaust outlet of the SCR reactor, a pressure difference sensing apparatus (40), and a control apparatus, a first control valve (21) being arranged on the air intake pipeline (20) and a second control valve (31) being arranged on the exhaust pipeline (30), and the control apparatus being connected to the pressure difference sensing apparatus (40), the first control valve (21), and the second control valve (31). The control apparatus controls the first and second control valves such that the pressure difference between the SCR reactor and the exhaust side of the diesel engine remains in a predetermined pressure difference range. The present system implements rapid ventilation and ensures precise control and stabilisation of pressure difference.

Methods and systems are provided for reducing emissions during an engine cold start. In one example, a method may include, during emission control device heating, injecting heated air into an exhaust runner of each cylinder of the engine during an exhaust stroke of the corresponding cylinder, after a blowdown exhaust pulse. In this way, an amount of hydrocarbons in feedgas provided to the emission control device prior to the emission control device reaching its light-off temperature may be reduced.