loss of power may occurr. however i didnt expreince any. let us know what you find.
the car only was rough at idle in my case, and any throttle applied it smoothed out

 

Correct me if I'm wrong, but the inline check valve is only found in turbocharged engines, right? I have 3.0 V6.
Thanks!

 

You're right ... only for turbocharged motors ... that"s mybad, I forgot you had the 3.0

 

I believe I might have found out the source of my A4 3.0 vibration problem.
I found a little hose connected to a small plastic resonator ( 06c 133 911 b) leaking air.
This hose is connected to the air duct between the MAF and the engine causing the car to run lean on gas. The rubber hose apparently is not sold separatly so I have to get the whole hose/plastic resonator which only Audi sells for @ 90 us dollars.
I'm getting the part hopefully next week and I'm going to install it myself, and hopefully the car will run good after that

 

My replacement of the inline check valve didn't fix the vibration ... still searching for the problem.

 

How many vacuum lines does this car have. Car has vibration when idling