There is a black sticky substance sticking to the accelerator. What's the problem?

Hello, there is too much dust in the intake air. If the engine is abandoned and dust is added, that kind of carbon deposit will be formed. It is recommended to change the air filter frequently. I hope it helps you. If you have any questions, please keep asking questions. Have a nice trip. If there is something wrong with the car, ask the car master. 4S shop professional technician, 10 minutes to solve.