My cobalt has been having a stutter/bucking problem for a while now...It feels like the fuel is cutting in and out? Happens in 1st and 2nd (a few times a day not always) at around 2,000RPM with the clutch fully out and maybe 1/4 throttle...All you can do is clutch it to calm it down once it starts jerking..

Throttle body has been cleaned, new plugs installed..I ran seafoam through my last tank of gas and vacuum line..Maybe a dirty MAF or injectors? Fuel filter? I should probably take it in to get the cat replaced because there is a TSB on them clogging...

Side note - Not sure if its related or not but when pulling up to a red light or stop sign the revs bounce around a little sometimes as I stop...It will drop to 500RPM a few times and bounce back up..

Edit - No CEL

 

i had a very similar problem and it was the shitty ebay cold air intake that was on the car when I got it.

I went back to stock and its fixed. I had too rich and intake airflow codes though.

have you changed the fuel filter?

Dave

 

Mine does this now, and I swear it's my P0833. It doesn't set a CEL either, but it's in there.

TB/MAF clean, new fuel filter. It usually happens after shifting from first to second then 1/4 throttle, and the car will buck. I'll either press the clutch in then let out, or just hammer on the throttle and it'll stop.

 

Cleaned my MAF and air filter so I can check that off the list...If I shift out of first at anything over 4K rpm I can almost always avoid it...

Would a clogged cat possibly be causing this? I would think that would probably be a problem when under heavier throttle...

 

Dropping it off in the morning at the dealers to check and see if the cat is clogged...If it is then it gets replaced free under warranty...If not I pay $100 for them to have checked and pick up a fuel filter on my way home..

There seems to be allot of heat under my hood after driving, fuel economy is slowly getting worse...No rotten egg smell however?

It's annoying as hell driving and not knowing when it's going to happen...

 

Mine doesnt buck lime youre describing unless its raining which causes the maf to glitch.

Mine also does the rev bounce after stopping

 

Is your cobalt supercharged or N/A? I'm having the same problem. I read something a out the intercooler pump going out and causing some jerking, like a misfire. Not sure how true this can be. When you find out results please post.