Patent ID: 8857159

Claim:
An exhaust system, comprising: a main line including a three-way converter and a lean NO x trap connected to and positioned downstream of the three-way converter; a bypass line connected to the main line at an upstream junction and at a downstream junction; a valve connected at the upstream junction to the main line and the bypass line for controlling whether an exhaust gas stream of an engine is directed through the main line to the three-way converter and on to the lean NO x trap or through the bypass line to bypass the three-way converter and flow directly to the lean NO x trap; a temperature-control device configured to selectively control a temperature of the lean NO x trap; and a controller being in communication with the engine, the valve, the three-way converter, and the temperature-control device, and configured to: receive, from the engine, signals indicating whether the engine is operating in a rich cycle or a lean cycle; control, based on the signals received from the engine, operation of the temperature-control device to synchronize the operation of the temperature-control device to the engine operation indicated by the signals received; and control, based on the signals received from the engine, operation of the valve to synchronize the operation of the valve to the engine operation indicated by the signals received.