So im taking my 07 cts 3.6(i have the extended warranty) to the dealer tomorrow to get checked out but wanted to know if anyone here has experienced anything similar so that i know what to expect from the dealer. So lately my cts seems to sputter sometimes and it seems like its lost power.. Its not time for an oil change and i recently replaced the air filter. When i accelerate it seems to shift fine till its gets to 3rd gear, it sputters a little bit and shakes but if i step down on the gas more it goes away.. Once i get on the freeway it runs ok but still dont feel the full power. I also notice that it seems to run a little bit better when it has a full tank of gas but once its low it acts up the most. Dont know if this makes sense to anyone.. Ive tried using fuel injector cleaner but still the same. Anyone have an idea on what this can be? It just seems to be like in a different gear sometime when it shouldnt be (if that makes sense).. Also my check engine light has not came on..