99 Alero Rough Idle, No Engine Light

1999 Alero 4Cyl, 130,000 km
It is idling rough. No engine light is showing up. Can it be plugs or other simple things even though there is no engine light present?

Start by scanning it and look for pending codes, no way to diagnose this remotely.

I will do a scan then. There is no engine light though. It would be interesting to see if there is a code even with no engine light.
I know that sometimes there can be carbon build up in the throttle body that causes rough idling (with no engine light present). It can be cleaned out for results.
I will post my results.