Ok, so I just bought 2 credits to tune my 2008 chevrolet Impala 3.5L V6. I just have a couple of questions before touching anything. First of all, how can I tell what PCM this car uses? Secondly, when writing to the PCM, does this car have the type of PCM where I can write calibration only or do I have to do a "write entire" everytime I reflash it? I just don't want to be frying a PCM since it's still under warranty. Oh and does this PCM have the current GM technology built into it where the dealer can tell if it's been reprogrammed? That's it for now! Thanks guys! Attached is a stock copy of the tune if that helps.