Light On - No Code?!

[kbininger]

In my '99 I30, for months now my check engine light has been coming on. When I hook up the code reader I get no code, just a 0. So I clear it, it stays off for a while, then comes back on. I check it, get a 0, and clear it again. Any ideas what it could be? Car is running well. The code reader is fine because it worked on my wife's Passat.

[maxhopper]

Use the method described in the how-to sticky at the top of this forum to read the code.