04 Altima Idle Problem

I got P0507 RPM too high

once rpm reaches 1800 it drops to 1000, then 1800 then 1000...
i tried replacing the idle control unit, also tried doing that set sequence where you pump the gas 5 times, etc etc, wait till MIL light goes off..problem is , i waited for over 7 minutes, after the light flashes and goes steady, it wont go off