1.8 Pinin Mpi 52 plate problem

hey need some help or advice

I have a 52 plate 1.8 pertol pinin mpi engine which is running like a bag of poo the engine management was on so hooked up the diagnostics machine and found 2 fault misfire cylinder 1 which is now corrected with new plugs and leads. Then 2nd was catalyst failure bank 1 so replaced that still running bad. When your driving constant vibrations and shaken which my mate refers to my beloved as a plane taken off it lacks power climbing hills and feels like it being restricted like something is blocking it all engine management lights are away and is a major improvement from when the problems started but cant take anymore of this please help !!!!!!!!!