Nissan Sentra Service Engine Soon Light - Quick Question - I know what code Indicates

Yup, you are possibly hurting the engine.

So, what DOES the code indicate? What exactly IS the code?

You do realize, of course, that a lean cylinder can burn a hole through a piston…too much air for the fuel is like using a bellows on a fireplace…you can burn a house down if you continue blowing excess air in the fireplace. More chimney liners have cracked that way…