ok here goes..i have an '01 2.8l quattro 5-speed and i need to replace the drivers side catalytic converter. I have heard, from a few different sources, a few various things that has to be removed to do the job. Do i have to remove the transmission like 1 person told me? Does any1 have some info of some shortcuts to do this job?

 

nothing but the cat and o2 sensor should need to be removed. also their is probably a heat shield too for the cat... thats about it. get an OEM cat and you can bolt it up yourself or save some money and get a universal and have an exhaust shop weld it on. BTW if your drivers side cat is going, the passenger either already has or is soon on its way out. so consider replacing both

 

If you're not going to go to a high flow, get the factory spec cats, and replace them both. At some point someone used a universal cat on mine, and rigged the hell outta the rest of the exhaust. I'd post pics, but I can't find them at the moment. They cut and spliced what looks like 100 pieces to make the exhaut on my car, and they are the most leaking, sloppy, amatuer welds I've ever seen.

They used a 3" cat with 2.5" pipe and tried to fill the 1/4 gap on the sides with weld. It's all been pulled out now that the motor is out, and will be redone properly. For the record: just do things right the first time around.

 

heres the thing with 2.8 A4 the cats are part of the downpipe and run straight to the exhaust manifold so to remove the cat you need to remove the whole thing. when my exhuast finally fell off and i realized the cats were gutted i cut them off with a saw and ordered magnaflows from ebay and had a local shop wled on the cats and new flex pipes. i suggest this route because its cheaper since OEM cats cost about 200-500 each and my whole thing cost me about 300. the only issue have is the cats/heatshield rattle a little which can freak/annoy you.

 

There is a diy for a 4.2L A6 that member (mustang) wrote up that is pretty much the same thing as the 2.8L, so follow that procedure.