The way I understand it, the conditions have not being met to trigger the CEL. There is what they call "pending codes". I had that once, then they may completely go away, or eventually trigger the CEL.
I had once the P0173 which turned the CEL on, and P0170 pending. I cleaned the MAS, new air filter, and used silicon oil on the MAS O ring, cleared the CEL and it has't come back in 22K miles. Not even as pending codes with no CEL
Rene