My 96 Buick Regal's check engine light continues to stay on. I have reset it by disconnecting the battery and have filled up with new gas which worked for about 3 days. The engine seems to sputter once in a while either from a stop at a light or around highway speeds. I have noticed as well the gas gauge has started to float as well when turning corners. What would you say would be a good option at fixing this or the possible cause.