so out of nowhere, my 2004 audi a8 started behaving weird, when you hit the gas, it feels like the engine is choking and wants to die, it goes up to about 2200 rpm than falls to like 1700 or less, does that a few times before taking off. and once beyond that point, its like nothing ever happened.

it does this like every other time. to help you understand how it feels.. imagine you accelerate hard, or just accelerate while in 3rd gear, instead of shifting down, it shifts into 6th for a sec than lets say 5th than finally 2nd. something like that.

at first i thought it was the tranny shifting into wrong gears, but than it does the same thing in manual mode.

checked for codes, got cylinder #5 misfire and engine too lean bank1+2 error.

any ideas how to fix this? i checked for vacuum leaks in the intake but found nothing wrong, no loose hoses.

sometimes when i start the car cold i can smell exhaust really bad, like its not burning all the fuel...

stumped.