Toyota Repair: 96 RAV 4 Check Engine Light, emission control system, trouble code

Question
My 96 Rav 4 has 122,000 miles on it.  The check engine light recently came on.  The engine runs fine and smooth with no apparent indications of any problems. Since I have not replaced the timing belt, is it possible that the light is related to the need to change the belt?  

Answer
It's very unlikely that the timing belt will cause the check engine light, there is another reason.
Most check engine lights turn on because there is a problem with the emission control system so I recommend that the system is diagnosed to find out what the DTC(diagnostic trouble code) is and then you can get back to me and let me know so I can help more.