Bucking but No Trouble Found
My wife's 08 Cobalt (2.4 manual EFI) experiences bucking. It usually happens out of the blue when fully warmed up and in any kind of driving (local or highway). It just starts bucking and you have to push the clutch and rev it so it will clear. The bucking is pretty hard.
No check engine codes. My mechanic has cleaned the throttle body, replaced fuel filter and air filter. I clean the throttle body also , about every 2 months. It isn't really dirty except for a little carbon as if it has backfired. This seems to diminish it for a while but never really goes away. Has anyone ever experienced this? Suggestions welcome. Thanks