hey ive been on here a few times asking about misifres but i think i may have figured it out. In the morning or upon cold start and taking off even under very light acceleration in 1st right around 3k rpms it makes a sudden whistle sound and in 2nd around like 2000-2500 and just under slight throttle in the rest of the gears. The car would have mis fire codes for 4 5 and 6 and sometimes random misfire. Also on occassion it will have a wierd idle going up and down between 600 and 800 just like a vacuum leak. Ive been reading things and hoping this may be the problem what do you guys think? Also where are all the vac lines on the a6 2.7t.. i also have never replaced the f-hose maybe this could be a possibility?. i have the samco one just never installed because it seems like its kind of a pain.