95 Chevy camaro z28

I got the car about a week ago. It would drive fine
until a week after. I had put regular unleaded (87)
gas instead of supreme (91). It started jerking
when it was time to refuel and the check engine
light comes on when the jerking is consistent.  I
changed the gas to 91 the 2nd time I fueled the car
and it stopped the problem. 2 days later and it
started doing it again. The car doesnt overheat or
have problems starting and fluids are topped off. It
only jerks when its driving, and it stops when I stop
the car and put it in park (service light turns off) itll
drive fine for a bit and start jerking again.