| 摘要 |
An exhaust gas purification system for a lean burn internal combustion engine including a three-way catalyst, a hydrocarbon trap downstream of the three-way catalyst, a NOx trap downstream of the hydrocarbon trap, and an electrically heated catalyst located between the hydrocarbon trap and NOx trap. In one embodiment, the NOx trap includes an integral particulate filter having alternating blocked channels extending longitudinally. The inlet channels filter particulate matter and the outlet channels have a NOx absorbent wash coat for absorbing exhaust gas NOx. A method of controlling the exhaust system during cold start engine operation is provided to reduce cold start emissions. The method further includes a control procedure for activating the electrically heated catalyst for desulfation and particulate matter burn-off. |
