pls an idea of whats going on

I dont know much about cars but i know that something is wrong with mine. I have a 2011 aveo ls with 85k miles. About a month ago the check engine light would come on and off and nothinf would be wrong with the car. Right now it jerks when its parked and when im gonna take off. Once im driving that im at a steady pace it goes away until i let the car and turn it back on. Like ill go out it'll start doing it and the after driving it for a good while it goes away. But after i park and turn it on the next day it does it again. Ive some research and i keep seeing spark plug, but then my exhaust is also making weird sounds like sputtering. Any idea on what it is and how much to fix it ?

i would start with the plugs, $20 and a half hour of work. It might be fixed.

If the spark plugs aren't working the exhaust noise could be the gas exploding in the heat of the CAT. If you have/had a CEL then a good code reader might be able to retrieve it, if it is still on, get the code and see what it says.

It is most likely not a bad cat, as it would be worse with more RPM. You could have a tear in your intake pipe that is causing unregisters air flow. But this sounds like spark plugs. every 20k miles they need done.