1.4t Yedi How did the idle jitter get back? There is carbon deposit in the engine.

Hello, there are many reasons for idling jitter! For example, the throttle valve is too dirty, the ignition energy of the spark plug is weak, the oil supply system is insufficient or interrupted, the intake air is insufficient or the intake pipe leaks, the timing is inaccurate, and the carbon deposition in the cylinder is serious, which will all cause idle jitter. The specific situation should be treated according to the situation of your car! For reference only!