Engine controller

An engine controller configured to control an engine including an occlusion reduction catalyst in an exhaust device, the engine controller comprising:

• a fuel injection controller configured to control a fuel injection amount of an injector configured to inject fuel into a combustion chamber of the engine;
• an exhaust-gas-recirculation controller configured to control an exhaust-gas-recirculation device configured to introduce exhaust gas from the exhaust device of the engine to an intake device;
• a sulfur purge determiner configured to determine whether sulfur purging of the occlusion reduction catalyst is to be performed;
• and
• a sulfur purge controller configured to execute sulfur purge control in a case where the sulfur purge determiner determines that the sulfur purging is to be performed, the sulfur purge control comprising causing the fuel injection controller to perform a fuel injection such that an air-fuel ratio at an inlet of the occlusion reduction catalyst becomes rich and causing the exhaust-gas-recirculation controller to prohibit the introduction of the exhaust gas,
• wherein the sulfur purge controller is configured to execute sulfur-purge standby control in a case where a predetermined sulfur-purge standby condition is satisfied, and resume the sulfur purge control in a case where the sulfur-purge standby condition becomes non-satisfied after starting the sulfur-purge standby control, the sulfur-purge standby control comprising causing the fuel injection controller to perform the fuel injection such that the air-fuel ratio becomes close to a stoichiometric air-fuel ratio and causing the exhaust-gas-recirculation controller to prohibit the introduction of the exhaust gas.