can someone explain how to replace this sensor? P0050 HO2S bank 2 sen 1. where is this located and are there any tips for replacing it? my car is an 02 a6 3.0. thanks in advance.

 

anyone? i really need to fix this. my car needs an emission test and it will fail if i can't replace the sensor. any help would be greatly appreciated. thanks!

 

if it's the pre-cat O2 sensor, then it's a PITA!. I haven't changed mine out because it's very, very hard to get too and remove.

 

i'm not sure where it is. i'm hoping that someone can tell me that from reading the code.

 

That's the drover's side pre-cat sensor. I'm not familiar with the 3.0, but it is pretty hard to see on the 2.7T. It was kind of a pain to replace, but after you remove a few things, you can actually get your hand on it.

Take a look between the engine and the firewall on the driver's side. Trace the exhaust pipe. You should be able to see it if you look around a bit.

 

3.0L O2 sensors are extremely hard to get at, much harder than the 2.7T. Its a good thing its bank 2 because bank 1 is not coming out un-less you pull the cat.
To get the O2 sensor you want, you dis-connect both the cam sensor harness and the ignition coil harness on bank 2 then swing it over to the passenger side so its out of the way. Then remove both cam sensors (5mm alllan bolt), Now you should be able to reach around the cylinder head and feel the up-stream O2, its the one you can't see. The only way its coming out is to use a very deep O2 sensor socket with a universal attachment because of the stupid cat converter design. If you can't get it out your gonna have to do it the hard way and drop most of the subframe and lower the transmission enough to wiggle out the cat, I don't recommend you do this yourself or any of you for that matter. I'd rather light my shorts on fire than pull out a 3.0L cat, just be warned.

 

What about on a 2.8L?

 

2.8L is cake. You can easilly get to those sensors by removing all the wiring and plastic covers and crap and get them out with all different sorts of O2 sensor sockets and wrenches.

 

both sides can be done without pulling converters...it is a pita..but it can be done.

 

On the 2.8 as auditech79 stated remove the engine plastic covers- for the Left Bank (passenger side) O2 nothing needs to be remove except for cutting the ties holding the wire w/ the harness- On the firewall (left bank) you will seethree colored wire clips (brown, green & black)- The brown is theafter cat O2 (lf bank) and the Green is the after cat O2 (right bank). The black clamp harness is the before the cat- to remove this you will just need an extension for your socket- I recommend spraying each O2 w/ WD40 or similar product and let sit for minutes to break the seal- On the Right Bank (Drivers side) you need to remove the coolant reservoir (only 3 philips heads screws hold this on- just be careful you don't crack the plastic "t" in front of the reservoir. On the fire here you will see one big black O2 clamp/harness, this is the before right bank O2. Now the O2 is easily spotted-use same process as left bank. When replacing a new O2 make sure you buyand/or check that thenew sensor has"anti seize" grease. Also, I bought the special O2 removal socket for easier removal/installation. This socket has a slice on the side to allow the O2 wire to hangout.