Hey guys I have an 03 Trailblazer with 4.2 engine. I did a tune up recently, cleaned throttle body, put new fuel filter on, seafoamed through brake booster and put a little in the crankcase oil. Just changed oil today with Pennzoil Platinum 5w-30. Well the problem since then is that when I try to start it is like it has trouble starting. I mean it starts but there is a small hesitation. I went and bought a new Duralast gold battery and still the same thing. The truck runs great but this just happened when I did this tune up. It used to start so quick when you hit the key but now there is a slight hesitation. Anyone have any suggestions? Thanks.