Hello everyone today I plan on replacing my thermostat on my 2005 cobalt. Can someone please explain to me what tools i will need to do this. This all started because 2 days ago I stopped to get gas and i decided to put regular unleaded instead of mid grade 2 miles later my check engine light came on. The next day when i tried driving it the light went off however now when i drive it i have to watch my coolant temp because whenever i stop at a light while I'm idling the temp rises and rises yesterday it got up to 210 just idling in the Taco Bell drive thru for 5 to 10 mins. Any suggestions are great appreciated.