Method for controlling the temperature of the exhaust gases in an engine and the relative engine apparatus

Method for controlling the temperature of the exhaust gases in a turbocharged engine, in which the air is picked up from the supply line (2) and injected into the exhaust gas line (3) upstream of a catalytic system (8) for reducing the nitrogen oxide content, for example upstream of the turbine (7) in the turbocharger (5). The air flow rate is controlled according to the temperature that is required by means of a control valve (10). Engine apparatus comprising a bypass line (9) that connects the intake line (2) to the exhaust line (3) bypassing the engine (1).