Excelle HRV car idling in place after starting, about a minute later, the engine idling suddenly became low, and there was rhythmic jitter. It's not just any vibration.

If an outdated version of the computer is detected, some fault codes may not be diagnosed. Or the inspector is inexperienced.

In your case, the most likely cause: (1) Idle switch or idle control valve failure: turn on the air conditioner. If the engine speed does not increase, this is a fault. Check the throttle position sensor and adjust or replace it. (2) Air leakage in the intake pipe: Open the engine cover and start the engine. If you hear the sound of air leakage before, explain the fault, find the air leakage and eliminate the fault. (3) Cylinder shortage: When the engine is started, cylinder shortage is not felt. When the engine enters the idling state, if the cylinder is missing, it will cause the engine idling instability and jitter. Check whether there is any problem with the high-voltage wire, ignition coil or spark plug that may be replaced for you.