2002 Hyundai Sonata

2002 Hyundai Sonata

i have a automatic 2002 hyundai sonata 4 cylinder I believe. The problem that im having is that my car will be driving fine and then usually when when I slow down slightly or speed up quickly, my car will jerk and continue to run, expect now the check engine light will be on and I will be running at for instance 4 and a half grand on my rpm and ill be doing 60 mph when normally I should be at no more then I guess 3. This causes extreme gas use and im afraid wear and tear on my transmission. I have been told that this is a problem with my speed sensor, this that true?