last week my '04 discovery had the service engine soon light pop on. brought it to the dealer to check it out (still under warranty). they checked the gas cap and found it not sealing tightly. after replacing it, they pressure checked the system and found a leak detection pump was leaking and replaced it too. After a quick road test they declared all was good and sent me on my way.
Friday, the light popped on again. So, we're back at the dealer today to keep figuring this one out.
Oh well, rover is paying for it and for the loaner car.
I'll report back once I hear more and know more about whats causing this one.