Q: Acceleration issue with check engine and rpm issue

The rolling problem child is an issue yet again. Over the last few weeks my car was jerking and not wanting to accelerate. Yesterday I finally got a check engine light, went to auto zone and they said it was multiple misfires and recommended i purchase chevron injector and system cleaner. So we put that in and noticed the RPM wouldn't go past 2000. I took it to the dealership and explained the RPM issue and check engine along with the jerking and hesitation to accelerate. They did a diagnostic and came back as spark plugs. Im hesitant to believe that was my issue because today the car isnt jerking or have a light, but it seems off in a way. Like before it would fly up to 4000 Rpm and now it goes to 3 maybe if i speed. Just wondering if this is normal or if it sounds like a temporary fix.

My car has 103560 miles.
My car has an automatic transmission.