hey
and welcome to the forum
i assume you have done the basic of basic and have done a diagnostic?
there is a walkthough in the faq section for this
i suggest removing the boost controller for a start or disabling it so you run stock wastegate boost and see how the spiking issue is
is there a screw in the lexus afm as this is also used to control a/fs a wee bit to control idle n stuff
as for the password lock i have no idea, maybe the memory can be reset somewhere
1am now.. i'm tired, if i think of anything miraculous i'll post it up later hehe