Why does my upper chest or bronchs vibrate when exhaling hard? there's no phlegm/mucus/cough. quit smoking pot recently but never smoked cigs. normal?

Impossible to say: You need a physical examination of your chest, and may need additional tests, such as a chest x-ray, to really give an answer. Often, some obstruction in the upper airway, like a polyp or an aspirated foreign body, can cause such sounds, but usually there will be cough, sputum, mucus etc. You need to be examined if it is bothering or worrying you.