KIA K2 engine sounds dull and weak. What is the reason?

Ask the great gods, 17 KIA K2, drive to the third gear, the speed reaches 2000 rpm, and the engine sound is dull. What is the reason? If yes, it is suggested that the landlord check the throttle, spark plug and high voltage coil. ~ 1. Fuel problem, insufficient combustion leads to unstable engine idle speed and increased noise. At the same time, the combustion is incomplete and the power is reduced. In order to get the original speed, you will unconsciously refuel the door. So, of course, the voice is louder than before. Second, the engine lubricating oil and gearbox gear oil become thicker, and the viscosity increases, which makes the idle speed of the car unstable. It is necessary to increase the idle speed to make the car idle louder. Third, the lubricating oil thickens, the gap between cylinder and piston increases, the compression leakage increases and the combustion deteriorates. More fuel must be added to meet the previous load. In this way, I feel louder when I run a sports car than before. Fourth, the engine is damaged. Because novices are in the running-in period, they often slam on the accelerator in low gear and drive at high speed in low gear, which is fatal to the engine in the running-in period, and will also increase the noise and climbing power of vehicles in the future, which is also the reason why most novices later become louder. It shows that this car has a lot of carbon deposits, so you can consider cleaning the related oil circuits and nozzles. I don't know how long it's been since your car was serviced. Check first to see if the air filter is a little dirty. Another suggestion is that you go to the repair shop and ask them to help you clean the carbon deposit on the accelerator. Maybe there is too much carbon in the car. Check whether the oil quantity is just right first, and then consider cleaning the oil circuit, including throttle, air inlet and nozzle. If you can't accelerate or decelerate, check the following parts. Check the fuel supply system first, replace the gasoline filter and clean the fuel injector, which will affect the fuel supply demand standard of the engine. Second, check whether the power supply system and the ignition head of the spark plug are too large, resulting in slow tripping frequency and affecting the combustion quality of the engine. It is recommended to replace. Third, check whether the intake system and air filter are dirty, whether the vacuum tube is aging and leaking, and cleaning the throttle valve will affect the intake. Fourth, check whether the exhaust system and three-way catalysis are blocked, which affects the smooth exhaust. Cleaning or replacement is recommended. @20 19