When my car dropped average even below to 5km/l. I got everything changed, got scanned, retuned, very thing done. And I faced that issue after changing my auto transmission oil. And its improving from next tank refill, and getting better mileage. its now giving 7+ km/l at the moment. PAta nahi keya masla hua tha. Thora or wait karta ho agar mileage thek na hui tou will try this. ON long getting 14.5 approx with ac speed between 80 to 100km/h. these cars due to their brakes dont allow you to go over this speed limit lol. but for better average i guess itni speed boht hoti hai.
My exhaust has always the same condition like yours and with a proper water throwing. not getting any petrol smell neither. means beats is 2004 auto. 5th gear tou ha he nahi
4 he total gear hain. 