C4 S6 V8 4.2l Engine technology has anyone's idea?

hi,
I offer here also a s6 unfortunately the motor is running correctly
my VAT has read out the fan memory and then exchanged one of the two crankshaft sensors - why did my car 2 of them?
What did they trade?
is there a model 2 encoder that tells the engine when to ignite and says how the valves stand?
If so, where are they sitting and how do I get that?
my VAT has, as said, exchanged one of the two sensors - MATERIAL 40 € AND 110 WORKING LABOUR UNDER THE HAND
the other looks no more great, however, were his words ....
the sensors should only be accessible from below and are above the transmission ....
I've searched from above today and found nothing
Well, he ran really well for 3 days...
then the problem was there again - again in the vst error memory gives nothing :kotz:

trust VD there - no more bucks on the box especially since I drove in full range even more dellen into the box ...

you can sell the box now better when it runs

Help, where can I get a cut drawing or motor pictures from where can I see where these dinger can sit?
Has anyone ever changed these and can describe where they sit? And how I get there
or can see if my VAT has done anything except rip off

Thank you for your help