to your question about this....
you can use A2 or A3 for suply 12v to A22 and for the negative for the wideband lambda you need to use a wired method, not ground, the metter method is using the E4 wire
scheme for not used the secondary lambda:
internal shunts for keep the original harness:
scheme for use the secondary lambda:
this is my information about the adaptation, very very extended and you can do it without modify your harness: http://www.foroctr.com/viewtopic.php?f=16&t=489
this works good on a PRB, I think the PRD is the same scheme as PRB
if the admin of the site wants this in English, I can post it goodly for all you