Exhaust line for e.g. spark ignition engine, has silencer placed on by-pass branch arranged in parallel to nitrogen oxide trap, and three-way control valve connecting trap and silencer to chamber, where valve is placed far away from engine

摘要

The line has an intermediate silencer placed on a by-pass branch arranged in parallel to a lean nitrogen oxide trap (3). A three-way control valve (7) connects the nitrogen oxide trap and the intermediate silencer to an expansion chamber (5), and is placed away from an internal combustion engine, where the valve is electrically or pneumatically controlled. The by-pass branch is separated from an exit (6) of a decoupler (2).