I had my car battery replaced the day after christmas, that's the only repair lately. Yesterday my check engine light came on and when driving to work if I get over 60 mph it slows back down to 60 mph but keeps going. It also seemed to use more gas than usual.
Check engine light on
Have the computer scanned for code/s-you have a problem within the engine management system that caused the CEL to turn on-This is your starting point of diagnosis, finding out what's going on.