2000 A6 2.7T Diagnostic Codes Help

[mollymcdonel]

I bought a 2000 audi a6 quatro 2.7T about 2 months ago. It had the check engine light on when I bought it, and the dealership told me it was from the O2 sensor but assured me it would make no noticable difference.
I did notice things the more I drove it. My gas seemed to get used up faster that my roommates, who drives a 2001 chevy truck and comutes about 100 miles more than me per week.
Again the dealership said this was not caused by my O2 sensor, so I called an Audi dealer who disagreed.
Then, about 3200 miles later (I know because I had an oil change when I first got it and I was 2oo mi over when I changed it again) I got an oil change and immediately after, my car started to run very different.
It felt to me like it was not getting to the correct gear, or it was maybe slipping out? I felt it shifting very hard, jerking the car, and the RPMs were jumping way up before my speed even reached 15MPH.
I chose this car because I liked its quick get-up and smooth ride.
This change in its performance was dramatic and sudden.
Initially I thought maybe it was the transmission, but found out that I cannot just pop my hood and check tranny fluid, so I took my car to AutoZone and had it plugged in, to see if they could diagnose something more specific.
They got 4 different errors.
1) P1411 Bank2, Secondary Air System Air Flow Too Low
-Failed Air Pump
2)P1432 Secondary Air Injection System Switching Valve (A) Circuit Open
-Failed Air Pump
3)P1140 Heated Oxygen Senser- Bank 2 Senser 2 Internal Resistance Too High
-Failed HO2S22
4)P1122 Senser Heater Circuit Open Bank 2 Senser 2
-Failed HO2S22
They translated the error code printouts to me as best they could and told me I needed to replace my Throttle Position Senser and O2 Sensor.
I tried to buy a new O2 senser, and they asked intake or output?????
How do I know if my faulty O2 sensor is the intake or output? Which one do I buy?
New Throttle Position Sensers are only sold at dealers.
I have been searching for a used one but turned up nothing at all.
Do they have a nomenclature other than TPS?
That completes my question.
Thanks so much!
Molly Michelle