Did you have the code cleared from the memory? If not, have it cleared and then check to see if the code comes back after a week or so.

 

If my care is runnign lean is that bad? What could happen?

 

is the CEL light on?? if not its a temp stored code and probably caused by the engine failing to start at one time like taking a few times to start, simply clear the code and take it for a drive to reset the computer and it should be ok if you get the code back let me know what it is and ill check through my data,

most cases cars I have reset the problem didn't return