I have a 96 Civic hatchback. I put regular unleaded gas in the other day and it seems like since then my car has been driving bad. I tried putting in an octane booster, but it didn't help. When I drive the car seems to struggle until i reach around 3000 rpms. It does this in every gear but it more noticable in the lower gears. When starting in 1st gear the car drops to 500 rpms, almost dies out then jumps back up to 1000. After roughly 3000 rpms it runs strong though. My check engine light is on, but I can't get my senors checked because my car isn't communicationing with the machine. It was so bad this morning that my car would idle but when any pressure was placed on the gas pedal the car would cut off. I thought maybe my car is acting up due the poor gas with ethynol additive, but from researching it looks like it could be many different things. Anyone had a similar experience and could give me some help or know what is wrong?