Methods and systems are provided for carrying out on-board diagnostics of a plurality of components of an exhaust heat exchange system. In one example, degradation of one or more of a heat exchanger and a coolant system fluidically coupled to the heat exchanger may be detected based on a first temperature estimated upstream of the heat exchanger, a second temperature sensor estimated downstream of the heat exchanger, a coolant temperature, and a pressure estimated upstream of the heat exchanger. Also, degradation of a diverter valve of the heat exchange system may be detected based on inputs of a position sensor coupled to the diverter valve.

A control apparatus of a premixed charge compression ignition engine that includes an engine body having a cylinder and causes a mixture gas containing fuel and air to self-ignite inside the cylinder is provided. The apparatus includes a fuel injector for injecting the fuel into the cylinder, a water injector for injecting supercritical water or subcritical water into the cylinder, and a controller. The controller includes an operating range determining module for receiving a parameter and determining whether an operating range of the engine body is within a water injection range. Within the water injection range, the controller controls the fuel and water injectors to inject the supercritical water or subcritical water between a latter half of compression stroke and an early half of expansion stroke, and to start this injection at a timing that is after the fuel injection and before ignition of the mixture gas.

A control apparatus of a premixed charge compression ignition engine that includes an engine body having a cylinder and causes a mixture gas containing fuel and air to self-ignite inside the cylinder is provided. The apparatus includes a fuel injector for injecting the fuel into the cylinder, a water injector for injecting supercritical water or subcritical water into the cylinder, and a controller. The controller includes an operating range determining module for receiving a parameter and determining whether an operating range of the engine body is within a water injection range. Within the water injection range, the controller controls the fuel and water injectors to inject the supercritical water or subcritical water between a latter half of compression stroke and an early half of expansion stroke, and to start this injection at a timing that is after the fuel injection and before ignition of the mixture gas.

A catalytic converter includes at least one heating element that is configured to disrupt the direction of flow of exhaust gases which contain harmful toxic gases and pollutants and aid in removing and/or reducing said toxic gases and pollutants.