2003 Saturn Vue Cylinder 2 and 6 misfire codes also low ope

I have had a low operating temp code 4 a bit now but has not affected the driving of the vehicle. I believe need to replace thermostat. But just yesterday I seem to have begin loosing alot of power vehicle struggling to make any kind of hill and overall performance is poor. Got a cylinder 2 and 6 misfire code. Could the low temp code be causing the problem or is there a seperate issue? Anyone experience this? Thanks