Contour Enthusiasts Group Archives Forums Modifications Duratec Maintenance rotten egg smell

You will get that smell anytime you have raw unburnt fuel going down the exhaust into your catalytic converter. Most often it happens under acceleration and it can happen with new or old cats. It just means you are running a tad rich and probably won't hurt anything as most cars will do it. If you never smelled it I would think it odd honestly though a well tuned car would minimize it.