A residual gas cleaner, comprising a manifold assembly having at least first and second inlets and at least an outlet. The first inlet receives spent exhaust gas from an engine, and the second inlet receives clean gas from a fuel tank assembly. A housing assembly comprises a housing that is secured onto the manifold assembly. The housing collects the spent exhaust gas. The housing assembly further comprises draining means to drain the spent exhaust gas from the housing. A filter assembly comprises a filter extending from the manifold assembly and is housed within the housing. The filter assembly filters the spent exhaust gas to create filtered exhaust gas. The filtered exhaust gas exits the manifold assembly through the outlet to join the clean gas. The engine receives the filtered exhaust gas and the clean gas from the outlet.