im cam, a licenced diagnostic tech, and a certified emissions test and repair tech.
the emissions light will illuminate when the computer see's something out of its usual perimeters that it doesnt like.
this can be something simple as a fuel cap to a lazy converter.
this is generally nothing to worry about, as emission issues dont generally affect engine running
the areas this monitors are evaporative emissions, catalytic systems and o2 systems.
the only system that will give you any problems is the o2 sensor issues. this will generally use more fuel than normal. if the engine light is flashing, this indicates cat problems are happening. this is something to worry about and needs to be looked at immidiately. .
i would not be to concerned about it, but would have it looked at in the near future when time and money is at a convenient.
you can drive it as normal, but if you notice anything in the quality of running , than i would take it in promptley
if you need any more assistance id be happy to help!
thanks and i appreciate positive ratings!