Please help me. I have already spent hundreds trying to figure out this problem. I have a 2005 Chrysler Sebring with a Check engine code P0491. I have been to chrysler numerous time since 2/17/2010 and they have not been able to figure out the problem. I have replaced a pcv valve, map sensor, cam sensor, and now a pcm. All of which has not lead to an answer as to why the check engine light will not go off and why it is giving this code. Please help I am going broke over here!