Noticing the rotten egg smell from the exhaust of my 2010 xr6. some say it is the catalytic converter working but I do not know. Does not smell very green to me. My old EL didn't have this problem. The car is going great otherwise. Would this be a warranty issue. Will drop in to Ford this Friday and see what they say. BTW using plain unleaded or premium fuels only. Staying away from the E10 stuff.