Have an 02 maxima, 130,000 mi, that is OCCASIONALLY overheating when idling. Replaceed the thermostat. Only does this on a hot Tenn day, 90's with high humidity. Temp in the 80's and it doen't do it. Doesn't do it all the time. Once you take off, it goes to normal. Fans seem to run high even when air is off. Tech said it could be obstructed radiator. Also occasionally get code for oxygen sensor but it will reset. Any ideas?