We're down to freezing temperatures in Minnesota and my car has tripped the 2B59 code. I cleared the code myself once and it came back the next morning. I was about to check codes again, but it actually cleared itself the next day (check engine turned off without intervention from me). I'm about ready to park the car for the winter and I'm undecided about replacing the thermostat sometime over the winter. Is it worth the effort to do it right away? Or, should I wait until next Spring and see if the code comes back during warm weather? Thoughts or comments?