Check engine light came on

[Mike - St Louis]

I have a 1996 318i and the check engine light just came on today. I have talked to several people and they tell me this is not serious but refers to an O2 sensor.

We have a 2003 Z4 and last year the check engine light came on in it, I called the dealer and they said driving the car was no problem just bring it in when convenient which I did. They replaced the sensor.

Is this a major issue, does the check engine light only refer to polution issues, is there a way to reset it?

Thanks in advance for your help!

Mike

[StLChris]

The O2 sensor can be the cause, but sometimes there's not even a real fault in the emissions system but a code shows up anyway. For example, my e36 thinks it has a bad gas cap.
Most likely it's nothing, but it's worth your time to find out what the fault code is. If you're anywhere near U City, go to Bavarian and they can tell you for sure.