While running errands few weeks ago i ran in store while my wife was in car with ac on. When i came back she told me she had to turn ac off because of rough running at idle. AC works great. Driving with ac no problem. I replaced iac valve and test drove car and problem seemed to go away. Next time i drove it problem was back. Going to check the positioning sensor for throttle next and get codes. 220,000 miles original owner. Thoughts? Do I need to reset something after installing iac? Thanks