"Service Engine Soon" light just came on my 2007 Nissan XTerra yesterday?

What is your question?

I just bought my XTerra 2 days ago and yesterday the service engine soon light came in. There are no weird sounds or apparent issues or anything noticeable, and it's running great. I researched a little and I read that it could be a loose gas cap, but I made sure it was tight. Is this something I should go and get checked out right away? Could this be because it needs an oil change/or to be serviced?

How long has your 2007 Nissan Xterra had this problem?

3 days