Some good news. . . as I prowled around a couple of the discussions on the P2188 error, someone mentioned they turned their key to ON but did not start the engine and then hit the scan codes/clear codes on the ScanGauge. That worked for me. Cleared the code again. It might have been a phantom. When I looked back at the dealer invoices I saw they had said they told me the code could come back. They did, but they also said there were other things they might have to do if it did. I wonder of one of those was to turn the key to ON and clear the code.