2005.5 B7 S4 Engine misfire/shudder, PCV Valve?
 

Hi everyone,

I was driving home for Christmas a few days ago when my 2005.5 B7 S4 started misfiring and stuttering on the highway. I was probably travelling about 75 mph, in 6th gear (manual transmission) and had cruise control on. Engine RPM was around 3k. The stuttering started immediately, it did not slowly start. I essentially lost acceleration power and was forced to pull over, and the check engine light was on. I had the car towed to the local Audi dealer.

The next morning, the dealer was started the car, and while the idle was a little rough, it drove nearly normally (except at idle). I was told that the PCV valve was "torn", and it would take about two weeks to get a replacement. While the dealer was able to explain why the engine was rough at idle, they were not able to explain why the engine was stuttering at higher RPMs. They suggested that when the valve went, the computer was not able to compensate for the change immediately.

Anyways, I have a few questions:
1) Does this sound like a PCV valve issue? I honestly don't trust this dealer, because it's not the dealer I bought the car from, and they don't seem like they are making the best effort to fix the car.
2) Are there any compatible PCV valves that would work in a 2005.5 B7 S4? The dealer is making the valve seem like the rarest part on Earth. If I could order a part that comes sooner than two weeks from now, I probably would.
3) Are there any issues/parts that I should ask the dealer to check in addition to the valve, which may be related to the PCV valve? What causes the valve to fail in the first place, or did I just get unlucky?

Sorry for the long post, I am just trying to get as much info as possible. I don't know that much about the S4, I literally bought the car a week ago and it pains me to see it in the shop already :(

Thanks for any help,
Ben