I have an 05 gt 5spd and sometime when I try to start it cold (either at night or in the morning) it will start with a stumbly low idle unless I keep my foot to the floor then it will slowly accelerate in rpm (I stop at 3k) and it will be fine for the day or even weeks. I bought the car with about 80k on it and it has about 150k on it now. Ive ran all grades of gas through it from all different stations and had no issues until now..except the alternator issue causing random check lights everyone has had, which I fixed awhile ago.