the only other difference between the 2 pulls was I filled up with gas in between the 2 pulls. Mixture of e85 and 93 just like I always do. But that shouldn’t be of any significance.

And yet bad fuel would be my first guess.

ACUSTRIP 987600 Series

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I noticed my ST was extremely sensitive to air density and a losing a noticeable amount of power with a 15 degree swing doesn't sound that far-fetched to me.

But as sobro said, it definitely could be fuel related as well since that was another variable.

My recommendation is to try another station at the end of this tank and hope the weather drops back down to 45 again, pull another log, and compare to the first log.

The accessport has a PID called ADC or Air Density Correction. I recommend you watch that parameter. Anything around 1.0 or higher is really good horsepower making air. Below 1.0 your power starts to suffer. Elevation and temperature are the main reasons this changes, but it gives you a good reading on how well the air is as far as horsepower production goes.

 

Yea I thought about the gas too but I always get from the exact same station and never had an issue so then I wasn’t so sure. I will try running the tank down and refilling.

while I do understand 15 degrees can make a difference, the temperature was still only 60 degrees during the bad pull. That’s still boost weather right? I can’t imagine going from 45 to 60 degrees would kill 45 torque and 25 horsepower.

One other thing I did notice is my LTFT seems to be stuck on 1 number regardless of throttle input or change in fuel. I run around e38 and I even tried adding an extra gallon of 93 to get the trims to change and they didn’t. It’s stuck at +10.94 currently. This has happened to me once before and I believe it was stuck around the same number. Then when I reloaded my tune and it reset itself and relearned and the trims would be between +3 and +7/8 depending on throttle. So I may try resetting my tune and letting the car relearn the trims again. Cause having the trims stuck at +11 means an additional 8% fuel in some areas. That isn’t enough to throw a code but enough kill some power as well I’m sure. So there’s a couple things I gotta try.

Would the density correction factor be considered one of those readings that are calculated from other sensors data and more or less “estimated” rather than being an official data point?

 

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Would the density correction factor be considered one of those readings that are calculated from other sensors data and more or less “estimated” rather than being an official data point?

It's just a proprietary number that ford came up with to determine conditions, most likely for the engineers. It is calculated from sensor data, you have 4 main pressure/temp sensors (baro, map, tmap, and the IAT/pressure sensor next to the airbox)and one external sensor (ambient air temp).
Again, just for comparison. Had you been watching this figure, you could confirm or rule out air differences between the 2 runs.

 

I checked it today and it was over 1. 1.030 I believe. Today was also back to 40 degrees again