idle issues. 02 focus. 1.6

driving me nuts now.

looked at a few threads about this but none have solved mine. Got a high idle when coming to a stop. Pull up to stop and revs will be just under 2000, then they will drop to just over 1000 then a few seconds later will drop to 750.

idle control valve is new and working. New plugs. Gave the intake a good squirt with cleaner.

not taken the air flow meter off yet, but it looks to be closing properly. I do have a hiss from the intake and thinking I have an air leak on the inlet. Just don't know if the hiss is normal. Sounds like its sucking air.

checked all vacuum hoses and all good and clear.

I do have an issue with revs. At 2100-2200 the car will shudder. Like its about to die. So at 65mph it shudders. But no lights come on as if its stalling. Does it through the gears at the same point. Still drives.

my eml light is intermitting, some times it will go a week without it on and then it will.come on for a few days then go out again.

speedo is also playing around but I'm thinking this is vss.

any help most appreciated.