Domo2e

Hi iam new to this ive a 07 220d vsc mode came on last 2 weeks ago traction control light and engine light came on lost power would not go over 2000 rpm . Pluged in the obd reader and p0400 code came up . Cleaned the egr valve out its was blocked car was driving fine for a day or two vsc light and all the rest off the lights came back on lost power after cleaning the egr valve i notice the engine is noiser the normal like a knocking sound ? Can anyone help and mpg is bad aswell i notice