will k04 turbo fit stock 01 audi a4 avant b5 1.8t
Hello , Here to answer automotive questions and make you feel comfortable and become familiar with your product.
Yes the K04 will fit, but a bigger turbo means that you will have a longer lag time during take off.
I recommend upgrading the ECM with a software flash such as GIAC or similar
I think GIAC is the best one out there.