Thread is now way off topic!
I had a chat to an auto electrician friend and he gave me some good feedback. he was busy and he doesn't have a 'Consult' as described in the FSM and wasn't sure if his scanning equipment would interface or work with the Pintara (being 25 years old )
He said then even though the inbuilt error checking may say no errors, he said that the oxygen sensor could be stuffed allow the car to either run I open loop mode, or run rich all the time. I checked with Supercheap and an 02 sensor is $43 -so cheap enough to just try it.
Regarding the high idle speed the suggestion is that the TPS could be stuffed or dirty or stuck or something. I will pull it off and give it a clean and try again. Around $80 on ebay for a TPS - assuming that is the issue.
I will let you now how I get on.
You may also need to verify that the TPS voltage when the throttle is closed, is approx 0.45-0.48 V, and when the throttle is fully open, it should read greater than 4.5 V.
PLMS do a usb consult interface (about $110 from memory), software is cheap if not free and will allow you to check these sort of things without having to touch wiring.
I've done the same in the past with my black U12 - changed narrowband O2 sensors, plugs / leads, all of that, never with any sort of tangible improvement. Narrowband O2 sensors typically don't cause massive fuel consumption issues unless they are erroneously reading lean mixtures. The O2 sensor only works in certain conditions too, ie low load / low rpm (5th gear cruise, putting around town etc).
My money is still on your thermostat malfunctioning or being stuck open.