ford focus 1.8 tddi?

hi i have a knock on my focus i dont get any smoke when i give it a boot full i only get the power when the pedel is hay way down if i have foot 2 the floor it does not pick up till i ease off i have changed the map sensor and the dpfe sensor i have had the car in to have it checked it came up with the fuel pump and the egr valve i have had the pump changed i took it back to get it checked again and there was no error codes but i still have the knocking