My car is idling from 2500 rpm to 1500 rpm at park. When I put it in drive the rpm is at 1500 rpm and does get any lower. I have tried to troubleshoot it by disconnecting the vacuum hose going to the map sensor and the erratic idling stops. I've also notice that if I disconnect the idle sensor the erratic idle stops. I have tried changing out the vacuum control box, switch egr valve, fast idle sensor, cleaning the and tighten the intake air control valve and nothing seems to be working.