my a4 1.8t has a missfire its number 3 cylinder that is the prob ive changed coil pack and plugs had the engine compression checked and the injector checked they are all fine so now im lost what to do . i did break the well i dont know what it is called it is on the air box and has two plugs on it i know its not the air flow meter as thats in the air box so if some one could tell me what this does and if it could be a problem or what the problem could be as im pulling my hair out

 

same problem here...

 

i just got some of the newest hitachi coils straight from audi and since i put them in they work amazing. I went through six or seven coils previously and I had so many strange backfiring problems you would not even believe. if it is not that little thing you broke try and check out these coils. They say Hitachi on them and i'm pretty sure they are the hitachi "e" coils but what i did was have my dealer/mechanic call audi and apparently they only sell them per VIN number but they refunded my money for the bad parts. i also took off my engine cover for less heat. good luck