I did my daughters A4 a couple of months ago. A little tight but not bad. You will have to order up.
all of the parts you need which will probably be the breather hose and the PCV valve which will invariable break (brittle with age) if you try to remove it from the hose. Take a good look at all of the hoses and be prepared to pull most of them even if good to clean the gunk out of the hoses. Clear the code and it should be fine when replaced. Just remember, most of the plastic connectors will break as they are brittle with age.
2003 Audi RS6 RNS-E, Catless Milltek, 6 Speed manual, KW V3
2001 Audi tt 225bhp Roadster, Blueflame, Kmacs, Defcon, Koni coilovers
2x 944 Turbo's ('86 & '87 Euro car n/sunroof)
1974 911 w/964 3.6 ltr motor
2006 Cayenne Turbo S