Hello everyone. I'm new to these forums and new to Audis in general. I recently purchased a 2001 Audi A4 and have had a few issues and need some help. First off, everytime I accelerate hard my car makes a high pitched whisting noise. It goes away after a few seconds. Also, my check engine light came on and I got it checked out. I have an o2 sensor that needs replaced. Could these be related in any way? Also, what is the cost to get an o2 sensor replaced at the shop. Any help would be really appreciated!

The two codes I got are
p0173
p0420

 

Do you have a 1.8t? And if so are you new to turbos? That may be what you're hearing

 

^^ I second the turbo,its the only thing,in the car that makes a whistling sound,when failing.

 

Nope I have the 2.8 Quattro. I have no idea what it could be. it's a real high pitched noise and is only there for a few seconds before going away.

 

Are you supercharged without knowing it?

 

lmao!!

 

i have a 2.8 Q also and i kinda hear a wine up noise also when punching it in 1st gear... but other than that i dont hear it... if you're askiing me i'd say its normal... its just a german thing

 

That's your transmission, mine did the same thing on my old A4 sedan. It's from the teeth on first gear.

OP, any chance you could get an audio/video clip of the noise? Diagnosing noises over the internet isn't exactly easy.

 

oh snap, really?? that makes sense now haha... i thought i was supercharged without knowing it LOL...

@ OP cca4 is right... if u can post up a video or sound clip or something that could really help us figure out what your problem is

 

Yeah the teeth on first gear chip and wear down, causing that whine. Google "01A transmission noise" and you'll find plenty of threads about it. Not much you can do besides rebuild it.

/threadjack