Unfortunately if your vehicle is a 96 or above, they will fail it if the check engine light is on.
You need to have a scan tool attached to read the code it's stored and then find out what needs to be fixed. Since you don't have a running problem it could be something simple.
You won't know however, until you get the codes.
Feel free to write back after you get the code and we can tell you what it means. Be sure and give us the year, make and engine size. Good luck.
〉 Answered on Apr 1st, 2008 by Lori Johnson, Owner and Instructor at Ladies Start Your Engines