how serious is the 'check engine' lite?

[wvicary]

Don't ever run/drive the car if the light is flashing..... can cause serious damage to the emission system.

[MNBoxster]

Hi,

The prudent thing would be to consider every CEL to be serious unless you find out otherwise. Try not to drive the car until the issue can be checked...

Happy Motoring!... Jim'99

[Perfectlap]

CEL can go off for the most minor thing like not screwing on the gas cap all the way (at least Three clicks). the light will not go away by itself, you need an OBDII scanner to erase the code and turn off the light.
What I do is to keep an OBD II scanner in the rear shelf. I picked it up on Ebay for about $100. Plug it in, read the error code number and do a quick search on Renntech.org to see what kind of problem it is. I thought of printing out all the codes and keeping that with the scanner.

[SD987]

Someone recently posted on this subject to PPBB with the following link. Although the article is long, I thought it was excellent.

http://www.aa1car.com/library/ic50234.htm