Hyundai Rena can't stop the car at idle speed, 1.4 automatic, electronic throttle, cleaned throttle, or can't stop the car without oil, please help.

This fault is related to carbon deposit, ignition system, oil pressure and electronic control system. First, check the carbon deposit of throttle body, idle valve, fuel injector and valve. If there is carbon deposit, clean it up first, and then observe it during trial operation. Secondly, check the use of spark plugs and ignition coils. Spark plugs should be replaced every 30,000 kilometers, and must be replaced when driving to the specified mileage. Secondly, check whether the signals of each sensor are normal. Inaccurate sensor signal or poor actuator work will lead to unstable engine idle speed. For this kind of fault, a comprehensive inspection is needed.