@phoenix1959 I have had both mucus plugs and nodules, the appearance is quite distinct on scans. Nodules are typically artifacts of infection, plugs are thick or hardened mucus that can get caught in the airways.

In my case, nodules disappeared a few months after the MAC infection was gone.

What finally cleared the mucus plugs was controlling my asthma completely which finally relieved lung inflammation, plus mucinex (just guaifenesinql and airway clearance with saline.

I have very sticky mucus (but no cystic fibrosis) and have used mucinex safely for 40 years. My kidney and liver function are both just fine. Problems generally arise when Mucinex is combined with Tylenol or dextromethorphan long term or excessive amounts are used.