Hi Carl, I had the same problem. Fault code indicated coolant temp sensor, which had alresdy been replaced by another workshop. Live data displayed a believable coolant temp, but a wildly inaccurate air temp combined with an inaccurate oil temp. I could not find an oil temp sensor. I wondered if without oil temp sensor, ECU estimated oil temp, giving favour to air temp on a cold engine. Then, going on the basis of two to one faulted the CTS. A new air temp sensor (part of MAP sensor) returned all readings to expected, and fixed problem. Tom