hi all i have a pug 306 which is idleing rough i dont know if its just me being a bit over careful and looking for a problem which isnt there but it idles rough once it has warmed up and idles only between 900-1000 so its not adsacly a massive gap but its just enoying i cant figure out why.

ive changed coolant sensor/ lambda cleaned the icv and check map sensor and as far as i can see it looks ok in paste reason i changed coolant and lambda because it revved from 500-3000 in paste turned out it was faulty coolant sensor due to was always in warm up phase as far as i can tell. but anyway just wanted to ask if anyone else has any ideas to what it could be
coil pack missfire?
faulty icv?
faulty map sensor?
leaking vaccum ( as far as i can tell its not)
or hate to say it head gasket on its way out?
as far as i can tell its not head gasket as no white smoke at all like its burning coolant no white crap on oil cap at all although does use bit of coolant but not massive amounts probaly litre or 2 max a month but think had faulty rad cap so cahnged it other day havent seen if has changed the consumption yet

anyway any help would be much appreciated
thanks alot michael