WHY is my car dieing when stopped and idling?

What is your question?

The engine light is on most of the time. Example today the car sat for two hours after driving to work with no problem. the car started fine. but when I backed out of the parking spot and put it in drive,with my foot on the brake the engine died. It started again with no trouble. I drove on the highway at 60 mph for 10 miles. the engine light was on the entire time. The engine ran well with no problem. When I pulled into my driveway I took off my seat belt and put the car in reverse to park and the engine light went off. It seems to idle low but doesn't sound rough. However sometimes it sputters or seems rough briefly when first starting to drive. The engine dieing is becoming more frequent. I am not sure if the problem is fuel flow or electrical.