2000 Peugeot 306 engine stutter

hello guys, my 306 when off the throttle slowing down gets to a point of gently snatching and then makes you think its going to cut out, as if in too high a gear, then feels like the pedal has been pushed slightly without touching it and pulls cleanly on tickover ! it has a fair amount of injector cleaner in the system but i cant say i noticed anything when purchase testing, but thats not to say it wasnt there, possibly just way i was driving it at the time eh ! it had a minor service this feb, i changed air filter already & have fuel filter in kitchen waiting, but i wanted some feedback first before doing it ! oh, by the way, it wistles away from about 1400 revs, turbo im guessing but hope its not sinister ??? thankyou !!! dave...