Willy77

That is what I was thinking. I'm not getting any warning codes. I thought I would if catalytic converter was not functioning properly. When the truck is warmed up and idling I don't get the smell. Only when slowing down or coming to a stop when in motion.

Two weeks ago I noticed a sulphur smell coming into the cab at slow speeds when drawing fresh air through the vents. No odor when A/C on max. I have had the truck into the dealership and they can't find the source. Anyone have any thoughts?