Hesitation while driving?

[Jaymz88]

Hey guys, its been awhile since my last post. Still check the site everydays though !!

I own a 2003 ecotec with ~117 km on it and have no problems in the past 2 years (Minus wheel sensor and broken strut spring). Anyways, since about 2 weeks ago, while driving on the highway, driving at about 1500 RPM and lightly feather the throttle, the car will occasionally buck or hesitate, whatever you wanna call it, while trying to accelerate.

Diagnosis from the aleromod gurus please

Thanks in advance