My 2.4 un my B5 00' is slowly dying(cam chain tensioners, bouth of them). So I decided to get a 2.8 form an A4/A6 and swap it in, when the 2.4 dies. The question is, how hard is it? Does the wiring match, do the ecu's and stuff match, etc.?

 

Yes, plug-and-play.

I gave a more detailed response in Audizine, not sure if you've seen it?