does it stutter or anything like that?
check your spark plugs and cables as well as coils make sure they are functioning right.
EGT's raising i'd say it has to do something with fuel, either you have a boost leak somewhere or lack of fuel to cool off the detonation. which brings me to the next topic, did you get my phone message about the injectors?
because i don't see a FPR on there with the 255 that you have, and with your stock injectors you are probably over running the fpr. especially with the stock injectors and this cold weather..
-E
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