I have a 02 harley supercharged truck, we elimintaed the two rear cats and did a bg fuel injection cleaning, now it idles higher, i replaced the iac with another one i had layingaround, it made no difference. i also looked for any vaccum leaks, none found!!!! the only thing i did notice was the iac in the resting position was partially opened, and when i tried to close it, it reopened. both of them were the same way.