Originally Posted by
mewantkouki
Re-calibrate your TPS voltage. My car used to do weird things in extreme temperature changes.
Or at least check it, so 10 points to griffendor Kevin!
RS-E tunes are 99% right, and if you're reading like you are with your AFR's, is most likely a mechanical failure somewhere.
+1 on having him run it on the dyno, at least a few pulls to see where it's at, and mybe help diagnose the problem in a controlled environment.