After clearing the code I started the car and let it run for a few minutes and the code didn't come back. The car was warm, though, from my drive home.

Here's the code:

16555 - Fuel Trim: System Too Lean: Bank 1
P0171 - 92-00 - Unknown Error Elaboration

I'm gonna have to keep an eye on it and see how it does after a cold start. Hopefully, it was a fluke. I had a code a few years ago and I had a mechanic clear it (this was before I had the VAGCOM) and it never came back.