I changed the air filter last August, so it should be good. I believe it gets changed anyway at my 64,000 mile service coming up in 1,000 miles. I think I'll just go ahead and do the VW O2 sensor thing to replace the one that seems to be going out. The car hasn't been performing quite as well as I would expect for a stage 2+ car, so I'll see if that helps. I may also replace the coolant sensor because my idle has been a little off.

Thinking about changing your cv boot? Read this first.
OEM Pressure Plate part numbers
Dead Battery?
My FATS Tests
How to install usb to serial converter for lemmiwinks on windows xp (UPDATED!)
Adjust the latency timer to 1ms if Lemmiwinks still doesn't work
Fuel Pressure Regulator Seal Kit
There is a second fuse on the back of the radio

*I am not a mechanic nor an expert in Audi repair/tuning. In no way are my posts meant to replace professional consultation.*