Check engine light + engine electronics
 

Yesterday, while my wife was driving home my 1998 E320 the "check engine light--engine electronics" message came on.

This morning, I ran a a couple of errands, refilled the tank and the check engine error message was still on. So I decided to check out hte codes and drove to my local Sears store to buy an OBD II reader. then, when I got back in the car to drive home, the error message was gone.

Does that mean that whatever was wrong, is not OK?

Does the car store codes, even after they are gone? I did not open the box for the OBD II reader (I plan to return it, sice I don't seem to need it now), but if the codes are still stored, I may take the OBD reader and figure out what the code was all about.

Any thouhgts on this? Thanks.

The code ( s ) should still be in memory, even though the light is off.