To me it feels like the car hits full boost right before 3k, id say around 2800 rpm. So it doesnt feel like its lacking any power it just makes a weird hissing noise between 3-4k especially when going up a hill.

 

One last thing about the error codes, this is the part i need right? http://www.ecstuning.com/Audi-B5_A4-...n_Sale/ES8367/

 

Just about the vacuum pipes and the engine surge when you first start it:

I recently replaced 2 vacuum hoses and for the first time saw my engine idle at ~1200rpm for a couple of minutes after a cold start. I put this down to the car revving itself faster to warm the engine and don't believe it to be a problem, am I incorrect?

 

You are incorrect. That's a leak.

 

Bugger. You sure?

 

Well, honestly, it could be various sensors and stuff, too, but a vacuum leak is most likely.

 

That looks like the right part, Peter, but if I'm not mistaken, the 2001 has a 5 wire O2 instead of 4 wire (5 wire is a wideband sensor).

That might just be for the upstream sensor. Can anyone else clarify?

I think Devil was saying in another thread, with ECS Tuning, you can give them the VIN to your car and they'll make sure you get the right part... again, not 100% on that... good luck, hope the sensor is your only problem, otherwise you'll be replacing your cat too...

 

Im pretty sure that its only the upstream sensor that is 5 wire but now I'm second guessing myself haha. Anyone clarify this please?

 

only the primary sensor on the 01s are wideband i think, so only the first O2 sensor would be 5 wire. you can call them before ordering and they will be able to tell you 100%.

 

k thanks ghost ill call and check with them.