| 摘要 |
In an engine with an exhaust gas ignition and catalyst temperature management system for raising the temperature of the catalytic converter during cold starts, air is added to the exhaust gases while the engine is still partly cold and operating in deceleration mode, even after a stoichiometric mixture is supplied to the engine combustion chambers, to force the catalyst to function as an oxidation catalyst rather than a three-way catalyst to prevent break-through of carbon monoxide and hydrocarbons. Air is supplied via pump 30, valve 32 and conduit 34 to afterburner chamber 16 between catalyst brick 10a, 10b. This avoids cooling brick 10a which is still being warmed to light off temperature and provides the excess oxygen necessary to oxidise the CO and hydrocarbons by means of brick 10b. <IMAGE>
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