Had problem with a strong odor coming from the.

Had problem with a strong odor coming from the AC vents. My Honda dealership replaced the evaporator unit (said there was leaking in there and mold was growing). Honda was really good about it and replaced it under my warranty (I was just a few miles over 80,000 which was my warranty), however it's back again. What should I ask that they do? When it was done I asked if it was all cleaned out and if there would be any mold growing back and they said no, it'll be fine. Thanks