Yup, it's because it hit 160,000 miles. It's usually a regularly scheduled maintenance light. Take a look in your owner's manual to find out what it is... I believe it's the 02 sensor, my book says to replace it every 80,000 miles. (I'm at almost 100k and I haven't replaced mine yet, I'll just run it till I buy a new one, or it starts giving me any trouble.) Do the maintenance if you want, or, if you are lazy, and you can do it yourself whenever you get time, or at least remember that it needs to be done sometime in the future....
Then flip the switch to turn the light off. On pre 96 Track/Kicks the switch to turn the light off is behind the left dash speaker on the right side of the opening. Take the speaker out, look around the right side for a little black switch, and flip it the opposite direction. If you have small hands (like me) you can reach up under your dash in that general area and feel for a switch, and flip it that way.
Hope this helps!

Heather