So I think I might have misunderstood how the MAT/CLT correct curve works on the MS. Based on this article at least (
Tuning the MAT / IAT Correction Table to eliminate Heat Soak), it actually subtracts a portion of the coolant temp from the air temp instead of adding it. They are taking the approach that the sensor is heat soaking and the air isn't. I'll have to think about my setup a little more on this one. I was thinking I had a backwards problem where my car runs lean at idle when cold, but then rich at idle while hot, even though it runs closer to 14.7 while actually driving. If it added CLT to MAT it would push the mixture leaner, but having just driven my car for lunch, I'm actually seeing it idle pretty lean when hot instead of rich. So the CLT/MAT correction curve would make more sense if it was pulling that temp back to richen the mixture up a bit. I guess maybe that could help my cold starts too if it's running lean there. I may try to follow along with their little guide of doing the scatter plot to see what I get.