2018 Mustang GT Idle Hang/Runaway

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I was working on a 2018 mustang Gt today that has had a checkered life... Flood salvage, Bad tune etc...
Car has CAI and catted longtubes

The last tuner tuned the MAF with a leak in the couplers on the cold air intake. The CAI couplers were fixed and I reverted most of the tune to stock and fixed the transport delay.
Now that the car wasn't going immediately into limp mode I noticed the idle RPM creeping up as high as I'd let it go. I could get it to come back down by blipping the throttle. It would idle correctly for ~15sec and start climbing again. I noticed that the Idle speed control mode would switch from "RPM Control" to "RPM Control No Learning." I sprayed brake clean all over to try to find a vacuum leak but couldn't

The car is also commanding an incredibly rich lambda even though the widebands are reading 1.0.

Here's the as found, my fixes, and a log of the issue. Thanks for any ideas.

if the spark tables are kicked up too much on decel it can cause idle hang too

Quote:

Originally Posted by decipha

if the spark tables are kicked up too much on decel it can cause idle hang too

The spark should be stock values everywhere. I can check again when I'm at my laptop. I'm really thinking there has to be a leak somewhere post MAF, or maybe in the card slot itself.