Spirited Driving Issue
 

This issue had recently started occurring where whenever I send the engine to red-line my AFRs all shift about 2-3 more points lean across the entire map. I can fix the issue temporarily by shutting off the engine then immediately turning it back on. I don't even need to pull over to reset it. I can literally just turn on the ECU and pop it back into gear on the highway then it runs normally again. I figure that it has to be ECU or software related if a quick reset of the ECU puts it all back to normal but I can't think of any parameters that would cause something like this.
A couple things about my setup:
'01 VVT
DIY MS3X
Naturally Aspirated
Can't think of any other relevant info that might help lead to diagnosing this issue.
Usually I can figure out the issues I run into on my own but this one has me stumped. I can post logs and my tune if needed.

Need a log to verify - basically make sure the pulsewidths are similar - but my random guess would be the wideband sensor is overheating. Where is it located?