I have been chasing this for a little bit. The truck has a new advance/delphi icp sensor, new motorcraft ipr. The owner had trouble with his icp sensor so he had been running it unplugged without issue. I replaced the icp sensor because the one on the truck was shorted. He called me and said at a hot idle the truck did it again today/cut offand refired when he unplugged the icp sensor. That sensor has been on the truck for maybe a month.. He has been told the harness can go bad but i have looked at it and there is no melting or oil at the connector end What should i do?