You know that the Lucas brand Fuel injector treatment has been tested to not do anything really good to clean the injectors. For best fuel injection cleaner, see a stealership, they have better stuff than what any parts store can offer.
I would pull out your intake tubing to the throttle body and eyeball it for any debris or dirt/grime on the actual throttle plate. If there is any buildup, that will cause hesitation and hiccups on throttle response.
2009 Cobalt LS XFE U74
Mods: K&N Typhoon Intake, Option Cat-Back Exhaust, Cosmo Short shifter, Maxxim Ahead 17X7's, MPx shorty antenna, FE5 Strut/shocks, Tein S Techs, Moog endlinks, Moog spring seaters, ZZP shorty header, LSJ downpipe, LNF front grille