ok, but I'm looking for a bit more concrete plan
Everything is possible, but an actual example is something different.
I'm not going to design custom active ecu based electronics for a power feed, because I dont know how and I dont know if it'll be reliable enough with temperature etc.
apparantly its not that simple.
Its for installing dual wideband lambda and narrowband converter btw.
A D+ simulator (which dre99gsx basically describes) that on its turn switches a contact on feed might work.
I dont want to blow my wideband sensors when for example I have to jumpstart my car. That would be pretty bad.
Jumpstarting my car because you cant drive with the result that you cant drive.
I figured out that the connector on the alternator (which on old cars is a D+ signal) on the m54 alternator is a bsd feed (bit serial data), so that is definately useless. But I saw that there is a second pin that isnt used. I'm going to measure that first to see if thats a dummy or some other feed.