hi,, i own an a4(b6) , while driving the car and most on highways, it suddenly loose power and about 3 secons later returns to normaly kicking back in.. and repeats this several times, getting worse and worse ... this doesn't happen when engine is cold,, most time this failure shows when driving for a long time,, ,, took it to audi dealer, scaned it, and din't find nothing wrong,,, i change ignitons coils, and clean the MAF.. but troubble persist,, any idea what should i checK,, i'm desperated!!, it only has 40K miles.. tnks

 

If you're under warranty, bring it back to the dealer.