Just Sc'd my Cobalt LE5 and I've started working with a tuner, and also learning how to work HPtuners. I can't believe all of the different variables that come into play when tuning an engine, its crazy. There is still so much to learn, but I'm starting to pick up things here and there. If anyone has any input, tips and tricks, please feel free to post anything helpful. I may get around to posting up a few logs, and the tune I'm running currently.