[EDGEFIND]

Alright, I fully admit that I'm pretty ignorant to the technical aspects of newer vehicles but being hard up for cash and having some mechanical ability I decided to take a stab at my wife's PT. It's her daily driver and, unfortunately, I only get to see it when there is a problem. The other day I noticed a coolant stain on the garage floor where she usually parks and asked her about it. She said that the coolant level has been dropping but she keeps it filled. At least she did that. I took a quick look at it when she got home and was able to see it leaking all around the thermostat housing and cover so I went ahead and picked up a new thermostat and o-ring to replace what was in there. I followed the Haynes guide step by step in removing the upper manifold and everything and then replaced it all putting everything back in reverse order. Now the engine light is on so I checked the codes which are:
P1684 Driver 5 Line 4
P0123 Throttle Position (TP) Sensor Circuit High Voltage
I had the battery disconnected so I expected the 1684 but what about the 0123? Anyone else have similar issues?

I figured I'd check here as everyone has always been extremely helpful in the past and am thankful for this forum's search function. I also need to replace the multifunction switch as the fog lights like to come on and stay on all by themselves and don't know if this is a related issue or not. Any help would be greatly appreciated. Thanks folks.