Hi guys, im new to this site, and new to Audi's and just having a couple of problems with a 1999 A3 1.6 8v. Now the A3's O2 sensor i think you'll agree is tricky to get to and i want to change it. But before i unscrew the sensor, i need to know where the plug is. I have traced the wire from the sensor at the back of the engine, to behind a metal shield at the firewall (rear end of the engine bay). I have a replacement Bosch sensor, so would rather replace the plug than cut the wires. Any help or how to's and/or pictures would be much appreciated. Secondly, the break pedal was travelling all the way to the floor and i was hardly getting any breaking. So i checked the fluid and there didnt seem to be any left Knowing there's a leak somewhere, i filled the system up with dot4 fluid and bled the breaks with the help of a friend pumping the pedal (i made sure he held the pedal down when opening the bleed nipple). I even bled them in the following order; 1. nsr 2. osr 3. nsf 4. osf. I thought that at some stage with fluid in the whole system, i can check where the leak is coming from, as a starting point. But now i cant see any leak, plus the level of break fluid in the cylinder/reservoir is fine and there doesn't seem to be air in the system anymore either. Also, breaking has improved alot, and all the disks and pads are more than fine. And even though the breaking is much better, it still only breaks after a bit of travel on the pedal. I know this sounds like air in the sytem, but i spent a fair amount of time bleeding each wheel, ensuring no more air is coming out before moving to the next. Does anyone know the reason for this? Could it be that it has to be bled with a pressure bleeding kit, or the break cylinder needs replacing? Or is it worth bleeding again, this time spending more time on each wheel, or bleeding in a different order? or is it something else? And last but not least (while im still here), what can i use as power steering fluid? I have both PSF and ATF dexron III, but have read that audi's stuff is a mineral oil and green in colour? I know that's alot for my first post, but obviously breaks are important and i dont want to take the car off the drive till its fixed and since the lambda sensor doesnt take that long, and makes my car idle funny and drink too much, i reckon i should change that now too (if the lambda dont fix it, i will look into the MAF). So any help is much appreciated. Cheers, Baz.