Method and system for operating skipped cylinders to provide secondary air

The present disclosure provides methods and systems for operating skipped cylinders to provide secondary air. Methods and systems are provided for providing secondary air to an exhaust system during catalyst warm-up. In one example, a method may include operating an engine in a thermal reactor mode in response to a cold start condition, the thermal reactor mode including skipping a first number of engine cylinders and generating torque via a remaining number of engine cylinders; and adjusting a cylinder valve of at least one of the first number of engine cylinders in a different manner relative to the remaining number of engine cylinders while operating in the thermal reactor mode. In this manner, exotherm may be generated by reaction of the secondary air with the fuel in the exhaust, thus raising the temperature of the catalyst. 本公开提供了"用于操作跳过的气缸以提供二次空气的方法和系统"。提供了用于在催化器预热期间向排气系统提供二次空气的方法和系统。在一个示例中，一种方法可以包括：响应于冷起动状况而以热反应器模式操作发动机，所述热反应器模式包括跳过第一数量的发动机气缸并经由其余数量的发动机气缸产生扭矩；以及在以所述热反应器模式操作的同时相对于所述其余数量的发动机气缸以不同方式调整所述第