Welcome to AF !
Your two threads have been merged. No need to post duplicates.
The best way to find out what's wrong is to get it scanned.
Just a misfire could cause the engine to run realy rough. And trip the service engine light. The trac off isnt going to affect the engine running or not.
Also when you first noticed the engine was out of oil. Had it just been running ?
If so the oil may not have had time to run back into the oil pana and give an accrate reading.
Has it had a tune up (plugs-boots)recently ?