Hyundai Accent 98 problem

Hello, how do I have a Hyundai Accent of 98, a few days ago that my car boots as explosions through the exhaust tube, I feel that I lost power I took it to the mechanic and took out the spark plugs and were soaked in gasoline, for this the same thing happened to me a long time and the mechanic took the injectors and saw that 2 of them injected more gasoline than the others I read there that can be due to this. Injectors Now several times I have already taken out the spark plugs and continue wetting with gasoline what could it be?

The valves could be failing but there are multiple possibilities, check this first of all. All the best.