smoking yawningI quit smoking about 2 months ago and can't stop yawning. Is there any connection or is it just a coincidence?

I doubt there is any relationship.
Yawning is a sign your body isn't getting enough oxygen.
Go out and do something physical. Walk, ride a bike, jog. etc.
I workout every day for an hour to an hour and half. I do weight training and cardio, such as jump training,smoking yawning core, and others. So I doubt that lack of physical activity is the reason.

My new theory is that my lungs are going through a healing process and are testing there new abilities.

Maybe since you stopped smoking smoking yawningyou can't find what to do with yourself. Maybe you yawn as a new habit. When i quit smoking i started chewing toothpicks for a while.
It's been two months so i doubt that it is smoke related. If your getting enough sleep then maybe coffee could help.