A guy I know went for the biennial CA smog check and failed because he had replaced the ECU in his nonMB car with one from an earlier model. The test is that specific.
Brings up an interesting point. I read that some folks were worried that their cars might be affected by Y2K bugs. Several authorities said that ECUs don't have calendars. If so, how can anyone know how long in days the check engine light has been on?
Is it illegal to drve with the check engine light on?
Big brother must be bored.