Systems and methods for treated exhaust gas recirculation (EGR) for an internal combustion engine are disclosed. The internal combustion engine has an exhaust manifold discharging exhaust gas and an intake manifold receiving forced air from a compressor. One or more exhaust treatment devices treat the exhaust gas and produce a treated exhaust gas. The EGR system includes an EGR line downstream of the one or more exhaust treatment devices and connected to the engine intake line downstream of the compressor, wherein the treated EGR line recirculates the treated exhaust gas to the intake manifold of the engine without passing through the compressor.

Systems and methods for treated exhaust gas recirculation (EGR) for an internal combustion engine are disclosed. The internal combustion engine has an exhaust manifold discharging exhaust gas and an intake manifold receiving forced air from a compressor. One or more exhaust treatment devices treat the exhaust gas and produce a treated exhaust gas. The EGR system includes an EGR line downstream of the one or more exhaust treatment devices and connected to the engine intake line downstream of the compressor, wherein the treated EGR line recirculates the treated exhaust gas to the intake manifold of the engine without passing through the compressor.

A system may include virtual sensors representative of operation of different portions of a tangible system. The virtual sensors may receive measured characteristics of the tangible system and may separately output values representative of operation of a common component of the tangible system based on the one or more measured characteristics input into each virtual sensor. A controller may receive the output values from the virtual sensors and determine a state of the common component by comparing the first output value with the second output value.

A system may include virtual sensors representative of operation of different portions of a tangible system. The virtual sensors may receive measured characteristics of the tangible system and may separately output values representative of operation of a common component of the tangible system based on the one or more measured characteristics input into each virtual sensor. A controller may receive the output values from the virtual sensors and determine a state of the common component by comparing the first output value with the second output value.

Systems, apparatus, and methods are disclosed that include an internal combustion engine having a plurality of cylinders and controlling a device to reduce the pressure in an exhaust gas recirculation loop in response to a pressure condition exceeding a threshold.

Systems, apparatus, and methods are disclosed that include an internal combustion engine having a plurality of cylinders and controlling a device to reduce the pressure in an exhaust gas recirculation loop in response to a pressure condition exceeding a threshold.

Methods and systems are provided for adjusting a substitution ratio based on water in a combustion mixture of a multi-fuel engine. In one example, a method includes adjusting a substitution ratio in response to an amount of water provided to a multi-fuel engine configured to combust a first fuel and a second fuel, the second fuel different than the first fuel.

Methods and systems are provided for adjusting a substitution ratio based on water in a combustion mixture of a multi-fuel engine. In one example, a method includes adjusting a substitution ratio in response to an amount of water provided to a multi-fuel engine configured to combust a first fuel and a second fuel, the second fuel different than the first fuel.

Methods and systems are provided for an engine including a humidity sensor. Degradation of the humidity sensor may be determined based on a change in intake air relative humidity as compared to a change in intake air temperature or pressure, under selected conditions. An amount of exhaust gas recirculated to an engine intake is adjusted differently based on whether the humidity sensor is degraded or functional.

Methods and systems are provided for an engine including a humidity sensor. Degradation of the humidity sensor may be determined based on a change in intake air relative humidity as compared to a change in intake air temperature or pressure, under selected conditions. An amount of exhaust gas recirculated to an engine intake is adjusted differently based on whether the humidity sensor is degraded or functional.