Just wondering if there is a sensor or something to make the temp gauge work correctly on my 2000 TA? I thought maybe there would be an aftermarket sensor that would make the gauge read right rather than cold normal and hot.

 

Those are GM proprietary sensors mated to the gauges to read whatever they do read. If you change only one or the other it will do no good as they both work in conjunction with each other. The only way to get an accurate reading is to mount a separate sensor and gauge.