Hey Everyone,
I was wondering if anyone could help me replace my o2 sensors. I bought my o2 sensors from vast performance, so I have two to replace. My car is an 01 Audi A6 2.7T. From the looks of it, I should have to drop the whole exhaust system to do this job. Is this true? The codes that I am getting are bank 2 sensor 1 and cylinder 4 misfire. Could the cylinder 4 misfire be caused from the o2 sensor going bad or do you think it would be the spark plugs or coils? Any help would be greatly appreciated. I almost forgot to mention that I have the bentley's manual and it doesn't really explain anything about the o2 sensor removal or the exhaust. Thanks again.

Sean

 

For the front o2 sensors, you don't have to remove exhaust to do it. You just need a right tool to do it. The bank 1 is easier. A long extension (24 inches), a swivel and a o2 socket are needed to make the job easier.

 

thanks man, so any suggestions on the bank 2 sensor. I am already moving the coolant resevoir out of the way.

 

the other one is a little more tricky
you can find it on the passengers side under the engine its kind of tight but once u see the one on the drivers side ull figure out where the other one is ( search for forums people explain wiht pics )

as for the cylender misfire that happened to me 2, i just ended up replacing all six spark plugs........ i had like 90k and they were due
i also changed the coils just to be safe

youll eventually have to do that...... but u can check the spark and see if it need to be changed just incase its 123 from the drivers side starting from the bottom of the hood to 456 on the pasagers side starting from the bottom too

 

question, are you having performance issues? This misfire code, are you getting a CEL and the car is also performing incorrectly? I don't think these CEL's are related. The last time I got Bank 2, Sensor 1 readings was because there was a voltage drop from the battery and it turned out the battery needed replacement.
A poor battery could start sending random CEL's and these two messages really don't seem related. Just something to check.
How about clearing the codes, checking your battery percentage in the morning w/ a meter, and then see if the codes come back?

 

Thanks alot guys, I have replaced the bank 2 sensor 1 and ended up taking out one plug to see if it was bad and it was. So I went out and bought new NGK's and now that I have had the battery disconnected for about 2 hours, I do not have any codes. If you notice on the NGKs, you have little tiny electrodes and mine were not there. As you already know the plugs have to be gapped at .032 inch and mine, because of the missing electrode were gapped at .065. That is twice the gap and I figured that, that would cause the cylinder four misfire. I will wait to do the bank 1 sensor 1 until I pop the code. Thanks for all of your help.

Sean

 

Hey is the Bank 2 sensor 1 the driver's side pre-cat sensor? or the Passenger side pre-cat sensor? Im a little confused. And does anyone have the link to a write up on replacing bank 2 sensor 1?

 

B2 S1 is drivers side pre cat

B1 = Passenger side
B2 = Drivers side
S1 = Pre cat
S2 = Post Cat