Help required

[Deeds]

Hi guys just looking for some help regarding my 2002 mk6 1.4petrol fiesta acting funny. 

Basically when I’m driving it has no power between 3k rpm and 6k rpm and if i put the foot down it just revs very loud and fast until it gets to 6k then kinda gets a little boost. Its very strange also I believe this to be related, when I'm changing gears the revs don’t drop and if i put the foot down after a gear change it does the loud/fast revs until reaching 6k rpm then boosts in. 

I’ve tried researching it and although not finding the exact problem that i have some suggestions have been cleaning throttle body/ idle speed control/map sensor/maf sensor/speed sensor/crank sensor. 

Im lost were to begin haha any help is greatly appreciated.