It didn't take a while to react and ignite, and Epc letters appeared on the dashboard. Is it the fault of the throttle?

Epc is the abbreviation of electronic throttle. There are generally two reasons why epc lights are on. One is that the throttle and sensor are out of order. Second, the brake light switch is faulty. Your situation is obviously a fault in the throttle position. It has seriously affected the power of the engine, and there is an error in the induction of intake air, which needs computer detection and maintenance.