My temp gauge flutuates from hot to regular temps, could a faulty 02 sensor make the temps fluctuate??? THe check engine light only comes on during highway runs, and I checked the ecu and it's code 1 = 02 sensor. so does the 02 sensor effect the temp gauge in any way???

 

Does the Code 1 get thrown, when the temp guage starts going up?

Pull your plugs and check their color, that should give you sone idea where to look.