I have had my 94 Runner for 6 years it has 230k, 31" tires, new plugs and fuel filter, K&N w/cold air. I typically get 17mpg town and 20 hwy in summer and 1-2mpg less in winter. This winter the mileage dropped to 14 or less. I have noticed that when I warm it up in the morning the high idle seems to stay on much longer than normal and sometimes it will idle back up after driving for a while. I think the poor mileage and the inconsistent high idle could be related. Can anyone tell me the location of the temp sensor that controls the high idle? Or am I on the wrong track?