Engine code P0725 Engine speed circuit malfunction

Check engine soon light came on with code P0725 Installed new battery, checked alternator, installed new Crank position sensor, car running good now no low/rough idle or lack of power but code came back? After clearing code it took 30 40 miles before coming back. What else can be causing this? especially since car seems to be running fine? Oh it's a Lancer 2008 2.0 non turbo