Had been ocasionally noticing the smell, so opened the cover to check the EGR valve. Looked clean, unliked in the picture.
However, on the passenger side of the engine, I noticed some burn marks, suggesting fumes could be escaping. See the picture from yikes98.
P.S. Also saw they spilled urea all over the engine bay after last DEF refill. Now have these white spots everywhere. Mad about it.