I have a 2000 mazda protege 1.8 liter dx. and my check engine light came on, i got it tested by auto zone and they printed the codes in which non of them were for mazda. they said that nothing is wrong with it and the codes are only for suzuki. and he turned the light off. but like 20 mins after it came back on. the car runs like a beauty. im not great with cars but i do change the spark plugs and get oil changes regularly. the light has been on for a total of about 40,000 miles now. im still getting good gas milage and i occaisionally go back to auto zone and the same thing happens. is this a huge problem? and how can i get this stupid light off?