Diesel engine control system

A system for an internal combustion engine (10) that enables continued regeneration of a diesel particulate filter (24) during deceleration is disclosed. A fuel injection pulse (64) is made with a minimum amount of fuel during deceleration. This enables the exhaust gases to be kept at a higher temperature. In addition, post fuel injection (66), air inlet throttling (68) and exhaust gas recirculation (70) can be utilised during deceleration to increase the exhaust gas temperature.