Rep Power: 0

So, about 3 months ago my radiator hose blew and I didn't realize it until I saw the temperature gauge pinned. (I have had no other problems with the car other than this since.) Ever since, the gauge has been incorrectly displaying the correct temperature. (Ex. the engine will be at normal operating temperature but the gauge still reads completely cold.) It takes a very long for the computer to realize that the engine is up to temp, and when it is it will finally shift in to overdrive. Otherwise, it's pretty much killing my MPG's because unless I drive for 30+ minutes I only have gears 1-3. Im assuming this is the Coolant Temperature Sensor thats bad. My question is: Could it be coolant thermostat, and should I try replacing the CTS, or both the CTS and thermostat?