99 Sunfire Problems

The Check Engine Light is on and also, I can't turn my ETS back on. It displays that it is off, and when I push the button, I can't turn it off.
Any suggestions???

Also, I had to pull my thermostat out of the coolant bottle the other day, and it was frozen in there. In the process of getting out, I broke the housing. Can someone explain to me what parts are needed to put it all back together?
Thanks,