408 1.6T proudly, suddenly the cold car started and stopped shaking. What is the explanation?

When the cold car is started, in order to meet the exhaust emission standard, the engine must be warmed up quickly (the three-way catalyst does not give an alarm) (ECU controls it according to the situation-such as throttle, thermostat, water temperature sensor, idle motor, etc. ), and ECU will correct the fuel injection quantity, correct the ignition advance angle and control the idle motor according to these comprehensive information, which will increase the fuel injection quantity when the engine water temperature is low.