I have a 2000 mustang
gt, when I start it in the morning, it will act like it wants to die. Battery is new, alternator and starter are fairly new. The engine was replaced and it has 80,000 miles on it. The tranny was rebuilt, and the rear end gears were replaced with bigger 4:10 gears. Tires are 18's. So the speedometer is off, but my O/D light is blinking too, it also revs up when I get up to 70n mph and will not go into overdrive. I have replaced the IAC valve myself and that has helped the idling. It feels like its not getting enough air. I also have an O2 sensor that needs to be replaced and will replace that soon. And when I get out on the highway to go to work in the morning it will bog down and act like its going to die, let off of the gas and put foot back on to gas and its fine. It only does this when it hasn't been started for a few hours. Help?