First off, I tried to look up these issues and could not see anything in the forum but here we go... I have a 2002 A6 3.0 Quattro with 130k Miles. The problems began when I had the P0741 TCC Solenoid Stuck Off Code as well as the P0420??? (I cant remember if this was the exact code but indicated the CATS were bad.) The car also shook bad right around 70 MPH and it had a rough idle. I took it to a mechanic who told me the cv axles, the CATS and the Torque Converter, so I went ahead and dropped the transmission and replaced the CV axles, torque converter, CATS and the O2 Sensors since I had easy access.. After putting it all back together I fired it back up and immediately noticed a loud sucking noise coming from the engine and a very rough idle... Turns out the "Spaceship looking" vacuum part was making the noise and had gone bad. I had It replaced and the idle is perfect now.. The issues I still have are:

1. Upon acceleration the RPMs kind of "Jolt" or "Wander" up and down.

2. At 70 MPH, the car still shakes and sometimes VERY violently!

3. The windows don't roll up, they start going very slow and get stuck..

4. I went in the car wash and ALL of the interior lights randomly turned on.

5. (Not as big of deal as the others) The temperature keeps automatically changing to celcius.

Sorry for the long post, any help would be greatly appreciated!

 

I forgot to mention, the CEL is OFF...

 

I'm not an Audi expert at all, but most computerized cars have to have the computer reset once you replace or disconnect any sensor or actuator. Try disconnecting your battery for an hour or so (or even overnite if you can). Once you hook it back up, let it idle for a few and then take it for a 5 or 10 mile drive and then see what symptoms return.

 

Do you have access to a vag-com? I certainly won't claim to know anything about the 3.0 let alone a cvt. Does the 02 3.0 have a CVT transmission? I'm pretty sure it does but I didn't think cvt's had torque converters. But I'm sure I am wrong. Anyways
#1. sounds like a torque converter issue
#2. ?
#3. Window clips (front can be replaced, rear requires new regulator)
#4. see if the carpet is wet under the front seats. Better yet, pull the seats and check to make sure the computers under the seats are dry. Also pull the battery and clear any debris below it that might be blocking the drain holes.
#5. Someone else on this forum had that problem a while back but I can't remember who or what was the outcome. Maybe search some more.

Hope this answers a few questions.

 

look behind the engine where the battery is and see if there is water in there. the drain hole in there gets plugged easily and the entire area back there can fill w/ water and leak into your car where it can damage your tcu.

 

the tcu isn't under the floor in an 02

They must have rethought it that year Dah!

1) I'm with Jeffla could be a TC issue- resolution, craiglist
2) new tires, I use Brigdstone pole position but Michelin energy or Perrelli pzero-nero are good
3) try at least shooting them with silicone to help lube the tracks
4) Wash your car by hand WTF your not under warranty anymore!
5) If it always C than you can convert it back to F, Happened to me once.
Read the forum and I'll check my notes on that repair

 

Mine started to switch to celsius about 30k miles ago and I have not been able to permanently reset it back to F. I can force it back by pressing the driver's side temp "+" button and the recirc button just above it to the right at the same time. But mine usually goes back to C upon starting the car again.