I have an 04 base auto, spark plugs changed, tranny fluid changed, oil/oil filter changed, have an aem sri, replaced valve cover to an itr one with new plug seals/new gasket, have the stock header/cat and hks hi power catback. Also have replaced primary 02 sensor. I still get a rich smell when accelerating somewhat harder than normal and when I start to approach 75-80 mph and definitely if I'm going over that. I've tried to search threads and all I've seen is burnt clutches, but unfortunately i have an auto so I doubt that info helps. Could it be something with the tranny? The brakes are only a few months old. The car is slightly lowered with eibach springs. Thinkin of taking it to a shop for troubleshooting, the car drives fine, that smell just bugs cuz I know it's bad to inhale those fumes. I've also changed the cabin air filter. Would problems to the a/c cause this smell? Trying to get help before i take it in to a shop.