2003 Mitsubishi L200 power loss

Hi. Management light came on. Engine tick over no power. Turn offf and on good for seconds then happens again. RAC came told egr valve. Took of power supply and blanked pipe. All ok for day or so and did same. Took of valve cleaned back with power and pipe connected. All good day or so same again. Bought blanking kit and told try with valve of and pipe blocked. Half a mile. Power loss so put valve back on with blanking gaskets fitted. Connected power and pipe still doing same. Only happens when gets hot. RAC again today and laptop saying airflow valve sensor which was told the one that which gives power to the top cooler and when disconnect it turns it off. He reset the faults and says that may help as car does not no what bits sorted if that makes sense. Will replace switch that like elec fitting one end and screws into the housing and that part is a 17mm brass fitting. Also it showed a fault with the air boost switch which is connected to the right of the same housing if U looking at the engine straight on but he said don't change that til done the first sensor as that would prob make switch show faulty. Very long winded sorry but the cooler comes on even when cold and not when hot til management light comes on. Leave with it running but not engine running. Cools down and then ok for a bit. Does all this sound like what making probs. Also told to connect inlet and outlet by a pipe and take off inter cooler. Thanks for time