Hi Lads, anyone know!

on tick over the revs go up and down only very slightly as thick as the needle say! but you can hear it and its noticeable, also noticeable when driving at constant speed, for instance on the motorway at 70 it feels like is going forward then the revs drop and slows the car then speeds up again.
Standard UK Turbo MY99 no mods !!
just put new Prfb6 plugs set to 0.7 but seemed to do that before (i think)

 

Usual signs of a MAF on the way out. Do a search on here for testing, or get it to a dealer for a check, as it can kill your engine.