My friend has an '03 Tahoe, not sure if it's 5.3 or 4.8, but V8 and 2WD nonetheless. When it gets cold it throws a check engine light (haven't pulled the codes yet) and decides to idle low/erratic, especially when really cold.

I will pull the codes soon, but Fred said it might have something to do with the drive by wire kanuter? (not his exact words) and that J.C. and Buttkiss had similar problems? Anyone have anything similar happen? TIA.