My 2004 Hyundai Elantra GT started overheating at high speeds only with A/C on only. The instant I turn off the a/c, the temp returns to normal. Does that sound like a temperature cooling sensor? Replaced last year I think, if that's the problem, it seems odd it would be bad again.
Updated: 7-16. I should mention that I am getting a code for 02 Sensor #2, but I recently replaced both of those also.... (Less than a year) So now I'm wondering if the Catalytic Converter could be in play here?