sorry this repost, cause I post on the fox forum my 95 mustang gt some time high idle, it did before and I replace IAC and it fix it, but now it did again, my english is bad, let me try to explaint When cold it ran fine and some time jerking and check engine light on it high idle some time when it hot out side, but when I put in gear idle drop back down to normal some time car drive really strong and smooth, some time i feel like it have no power. and when ever the car is jerking while driving, I saw check engine light on first when I crank the car when hot, and high idle the check engine light flash 3-4 time then stop flash some time hard to start ? and some time need second crank to start, and some time after it start rmp drop and want to die. I take to friend shop and he cant get the code to come up. he cant scan the code. think im concern is, either bad maf sensor ? and is coolant temperture sensor have anything to do with it ? i heard is control air/fuel mix also ?