I had sensor issues too, so i just re-did everything with new Febi sensors, and the MJ-style ball joint linkages and sensor connectors from Sergey's thread and they have been working ok for the last ~3 years. The original plastic joints are crap imho and even if you get them to work with WD40 or whatever, they will fail again.
The calibration did require VCDS, (not vcds lite as it can't do it)
