Hello dear ones. I changed the cooling water thermostat some time ago. The engine didn’t want to get really warm in winter. Since then the engine control lamp lights up. Sometimes it goes off. Then it goes on again. Recently it stayed out for about 500 km. But then it went on again. I have already disconnected the battery several times. But it only led to the same problem. After the battery is disconnected, the engine has speed problems. p below 500. Then give a little bit of gas. That goes about 80 km. At some point he catches himself then. Recently I removed the engine control unit. The visual control resulted in a white stained edge. Elkos looked optically good. Lids were straight and were not arched. I cleaned the board with isopropyl alcohol and brush. After installation there were no speed problems. Battery I had disconnected before the ECU expansion. Engine control lamp lights up after about 15 km wi usually at constant speed on the highway or on the highway. There it goes out again. This morning the engine also had problems with the start. He usually stands in the garage. There he has not done it yet. But this morning he stood outside. I have a Mitsubishi Lancer V station Wagon with 83 kW and 113 hp. 1597cc. Year of construction 01.2000. Engine identification letter: 4G92. Maybe someone has an idea of what it can be. Otherwise he is currently taking good gas. and also has his performance. No matter whether the lamp is on or off.