Methods and systems are provided for accurately learning the zero point of an intake gas oxygen sensor during selected engine no-fueling conditions. The learned zero point is used to infer EGR flow and accordingly adjust EGR valve control. In addition, EGR valve leakage is diagnosed based on the zero point learned during a DFSO adaptation relative to a zero point learned during an idle adaptation.

Methods and systems are provided for accurately learning the zero point of an intake gas oxygen sensor during selected engine no-fueling conditions. The learned zero point is used to infer EGR flow and accordingly adjust EGR valve control. In addition, EGR valve leakage is diagnosed based on the zero point learned during a DFSO adaptation relative to a zero point learned during an idle adaptation.

An internal combustion engine includes an intake conduit fluidically coupled to ambient fluid and having an internal cross-sectional area and an engine cylinder fluidically coupled to the intake conduit. A fluidic amplifier is disposed within the intake conduit and is fluidically coupled to the ambient fluid and engine cylinder. The amplifier is further fluidically coupled to a source of primary fluid and is configured to introduce the primary fluid and at least a portion of the ambient fluid to the engine cylinder.

A non-return valve device for an internal combustion engine includes a valve housing comprising an aperture with a downstream end arranged in a duct housing. The aperture defines a flow cross section. A valve seat surrounds the flow cross section. A valve closing member, provided as leaf springs, adapts, closes or opens the flow cross section. A distance between each of the leaf springs in their maximum opened position at the downstream end of the aperture and the duct housing arranged opposite to each of the leaf springs has a maximum which is twice as large as a distance between each of the leaf springs in their maximum opened position and the valve seat arranged opposite to each of the leaf springs. Defining inner walls of the duct housing downstream of the valve housing are arranged so that the flow cross section is first continuously reduced and then continuously enlarged.

A non-return valve device for an internal combustion engine includes a valve housing comprising an aperture with a downstream end arranged in a duct housing. The aperture defines a flow cross section. A valve seat surrounds the flow cross section. A valve closing member, provided as leaf springs, adapts, closes or opens the flow cross section. A distance between each of the leaf springs in their maximum opened position at the downstream end of the aperture and the duct housing arranged opposite to each of the leaf springs has a maximum which is twice as large as a distance between each of the leaf springs in their maximum opened position and the valve seat arranged opposite to each of the leaf springs. Defining inner walls of the duct housing downstream of the valve housing are arranged so that the flow cross section is first continuously reduced and then continuously enlarged.

An EGR valve control apparatus includes: an EGR valve configured to adjust an exhaust gas recirculation amount of an internal combustion engine mounted on a vehicle, a detector configured to detect a caught state in which foreign matter is caught in the EGR valve, and a controller configured to control the EGR valve. The controller controls the EGR valve to perform an opening and closing operation, in which the EGR valve opens and closes a predetermined number of times, on condition that the caught state is detected by the detector when rotation of the internal combustion engine is stopped in a state where an ignition switch of the vehicle is on.

An EGR valve control apparatus includes: an EGR valve configured to adjust an exhaust gas recirculation amount of an internal combustion engine mounted on a vehicle, a detector configured to detect a caught state in which foreign matter is caught in the EGR valve, and a controller configured to control the EGR valve. The controller controls the EGR valve to perform an opening and closing operation, in which the EGR valve opens and closes a predetermined number of times, on condition that the caught state is detected by the detector when rotation of the internal combustion engine is stopped in a state where an ignition switch of the vehicle is on.