Various methods and systems are provided for blocking backflow of exhaust through an exhaust gas recirculation system. In one embodiment, a method comprises flowing exhaust gas through an exhaust gas recirculation (EGR) passage in a first direction from at least a first cylinder group of an engine to an intake manifold of the engine, the exhaust gas flowing in the first direction through a filter arranged in the EGR passage prior to reaching the intake manifold, and blocking flow of gas through the filter in a second, opposite direction with a mechanical one-way valve positioned in the EGR passage between the filter and the intake manifold.