hi everyone im new to this i just hope i posted in the right place. I just brought my first car and its a ef furtura and i have a small issue with it. when you give the car a large rev on idol on the way back down it will stall or just cut out and it will often do this on the road. I'm thinking it is a blocked fuel filter cause its sorta like the engine sucks out all the fuel and the filter slows it down, i thought it might of been not getting enough air but i pulled the air box and filter and and cleaned it and all that was fine. could anyone give me any suggestions on what it is and what i could do to fix it

Fuel pump could be on the way out.

More than likely the ISC.

whats i ISC??

sits ontop of the Throttle bottle has a plug on it and a black cap on it

Idle Speed Controller, adjusts the idle speed under different loads. May I suggest that you buy a workshop manual.