The check engine light should stay on. The spoiler shouldn't stay up either. If the spoiler is like the locks its vacuum powered, may be a leak somewhere in the vacuum system. My check engine light did not come on though when my deck lock went out. Is your gas cap on tight? I know that sounds stupid but that causes the check engine light to go on. Make sure its on tight. I'm sure one of the folks here has much more technical expertise about what might be going on.
Good Luck !

Pat