What does it mean when the check light (yellow) comes on in my 1997 honda del sol? Is it an emission malfunction? I always twist the gas cap about six or seven times to ensure its tightness and the manual said the light "should" go off after 3 car trips. Well, I have done 5 car trips and it's still on. What do I do?

Yes it is a emission problem, But the emmissions are a complete set of sensors, parts and wiring that does need replacement from time to time. Such as O2 sensors, temp sensor, oil pressure sensor, catalitic converter, vacume line, wiring, . you need to get the code from the ECU to get the exact problem diagnosed, Most any oil change shop can do this for free as long as thats where you change your oil, As soon as you get the code you will know the faulty part.