Yakbaas

First left me stuck after a 200km drive , we stopped for dinner and car won't start. Towed back home 1km, scanned and engine speed sensor fault showed. Got an aftermarket sensor from Goldwagen, fitted and all good. 3 days later started missfire but got me home, had to stay light throttle under 1400 rpm. Scanned again, crank and cam sensor showed. Got cam sensor from Audi and cam code is gone but, car starts and run fine until reaching operating temp. then missfire and cuts. After it cools down it starts again. Changed diesel filter, checked fuel pressure (ave 480bar) The Engine speed sensor fault shows again . I'm now thinking that the new sensor might be bad.
Any other ideas?