So, I had the work done. One valve was replaced the others got resurfaced. They did the timing belt, gaskets, the small turbo hose, etc. (It's all listed on the work order).
Drove it for about a week and it all felt pretty good. MPG seemed a bit on the low side, but I've done zero highway driving (sitting at 21.6 MPG over the last 150 miles).
Anyway, today the check engine came back on with code P0171. Super frustrating.
Possible that they missed tightening something up when they put it all back together? Front 02 sensor is fairly new. Only about 18 months old.
Popped the hood to see if there was anything obvious going on and it felt like there was air flowing up from the left side of the engine, so maybe an exhaust leak or a leak around the air filter? I can't say for sure, but I feel as though anytime I've looked at the engine while it was running before today and I never felt any significant amount of air moving on the left side of the engine.