according to my chart, 287 ohms is equal to 85C, which is 185F.....
So 290 ohms would be about 183F.....
Would like to see live data vs the gage data...
Was P0128 set?
I have had cars idling in the bay in the garage where it is warm, and the needle slowly moves up to normal......but go out on the highway and it drops immediately(especially in this cold weather).......fix, thermostat...