I have a 99 Civic Si that is having idling problems. It started after I used some intake cleaner on the throtle body and now after any hard driving or prolonged exposure to high RPM (4k+) followed by sitting at a stop light, the check engin light will come on and the car will start to idle at 1600 RPM. When i barely touch the gas petal or push the butterfly valve on the intake, the RPM will start to jump between 1600 & 1700 RPM and whenI push the petal a little bit further down, it will jump to 3000 RMP and hold there. I took it tomy mechanic and he suggested replacing the "idle air controler" which seemed to work, but 2 weeks later it was doing it again. I can never really get the problem to occur when he resets the computer and hooks his code reader up and goes on a test drive. I did have it doing it when I braught it to him but when he hooked his code reader up and reset everything, the problem was gone. When ever the problem occurs while im driving, I find that if I just turn the car off and let it sit for a min, then turn it back on its fine, the check engin light stays on but it will drive like normal, at least for a while. Some times it will do it again, some times it just fine. My mechanic has no idea what it is and doesn't want to just throw parts at it and seeing what works.
Has anyone had this problem? Please, this is really starting to annoy me.

 

not suppose to use that carb cleaner - it ruins a sensor.
think if i recall correctly, it is the MAP sensor.
ok, if older car and no map sensor