Thanks for all of your replies (and the part numbers, and the hyperlinks). I am starting to believe I may have been looking at the wrong sensor. I believed the CTS was just below the thermostat housing. The connector/harness coming off of that has 3 wires. I am able to pull the plug out of the sensor. I am also able to unplug the other end of the harness, and take the harness into the house with me. This other plug has the connectors in a row, instead of the triangular configuration in the plug for the sensor itself. After that plug, the 3 wires go into another, larger, wire harness and get lost in that. So the CTS harness comes out of the sensor, bends over the top of what I believe is the lower intake manifold (behind the oil fill cap), plugs into the main harness, and gets lost into the main harness. Just in case, I found a small length of rubber hose, put a slit down the length, and encased the wires in the hose. I am seeing posts that say I need to cut the wires and solder/splice the new stuff on, but I'm seeing a plug that I can disconnect from the rest of the system. If I am looking at the wrong part, please let me know.
Other than that, I drained the old coolant out of the system over the weekend. I believe the DEX-COOL coolant is orange in color, but what came out instead was a mixture of orange, green, and black. I believe the black stuff was some sort of leak sealant, because the coolant reservoir was lined with the gunk. I then filled the system with water, and ran the engine with the heater on high for about 10 minutes. I then let it cool off, then drained the system again. This time, the liquid was more orange than anything else. I then put some radiator flush stuff I bought (it was a blue PEAK quart bottle) in the radiator, and filled the rest of the system with water. The directions on the bottle suggest driving the GP for a period of 3-6 hours to really clean the radiator. I noticed the temperature reading has been a bit cooler, for it hovers around the 180 mark when driving, then goes up to just over 210 when idling. Sometimes it will get up to around 220 or so before going back down to 210.
