[Oldsguy]

Well, that smell is definitely very close to a rotten egg smell, I am sure you have experienced it before on SOME car in heavy traffic or at a stop light. You would recognize it again if that was it so it must not be your catylictic converter. Isn't there a way to read the number of flashes the diagnostics in the car's computer give out when you short two of the pins on the diagnostic connector? It seems that I remember reading about that? Just bringing that up as an option because it is much cheaper than buying a diagnostic reader.