coolant leak now more problems! help

Okay, it started out as a coolant leak, and so I put some stop leak in it, and no problems, but I knew I needed to find the leak and fix it.. being the female that I am, I bought all new hoses and such and went to replace them myself.
which was a task, i replace all the hoses, didn't unplug anything or do anything else, even flushed the radiator, now the car is running around 215 while driving and idle, and the service engine soon light is on as well as the trac off light, any suggestions, i really don't want to pay the $100 at the dealer for them to tell me there is nothing wrong.