I have a 2000 Jeep Cherokee straight 6 this morning when I started it up it idles High higher than normal at one point it was idling at 2000 I drove it anyway I had to get home on the freeway I can feel it missing then the transmission came out of here as I pulled over and slow down I put it in first gear and it would go into first gear drive or 3rd it was just slip I pulled off the freeway turned it off check the codes at the CPK and throttle position sensor code I reset the codes started it up it idles fine I got on freeway and it seems to drive fine. I have been having a problem a rough idle and it has been throwing a 1391 code I have replaced crankshaft position at least twice