Starter keeps cranking engine after starting.

[The1Dan]

My 2004 Cayenne S starter will not stop cranking engine. at first it was random. then it started doing it more and more. every now and then it would start up and run bad. i would have to sit and let it run like it was cold and needed to warm up. i live in arizona where its always warm, so that was ridiculous. after a few minutes it the idle would correct itself. the more the starter wouldnt stop cranking the more it ran bad on start up. i thought the starter was going bad so i replaced it. that didnt work either. brand new starter and it still wont stop cranking engine. i know that the power is diverted to the starter to start car and once it starter the relay shuts of the power to starter and it goes back to the everything else. i replaced the starter relay as well. i have repaired the wiring under drivers floor as well thinking that was the problem. i did the "reset" on the steering lock as well. checked all the fuses. replaced the relay for ECU. ignition switch is working. battery is new and fully charged. no codes to go off of. what is it that i am missing. the engine will start up and the starter will keep cranking. its a pain to remove everything to change the starter. its going to ruin something if i cant stop it from doing that.