I have a 1998 Civic Si (Canada - I think that's the EX in the US, but I'm not entirely sure). Lately I have been having a few problems with my car and I'm not quite sure what's causing them.

On a recent highway trip, I noticed that my cruise control was cycling between 10 km/hr (5-6 miles/hr) above and below the speed I had set it to. On another occasion, I filled the car to 3/4 full from 1/4 full and then took a highway trip that used about a half tank of fuel. By then end of the trip, when the gauge should have read 1/4 full, it was cycling between empty and half full.

I have also noticed that I cannot get my car to go into 'reservation mode' for the remote start any more.

Do you folks have any idea about what could be causing these problems? Could they be related? Since this is my first car and I am still in school, I don't want to spend a ton of money fixing this, but if there would be a relatively inexpensive fix, I would like to have my car running its best.

Thanks in advance for your help.