three out of four seem to work fine. Getting P1172 (bank 1 rich). The 'new' old driver rear sensor did not really move from .750 ish. Was an NHK. When the original sensor is unhooked, I get the .445 error which makes sense. Then I cleaned all grounds I could find. cleared codes. Replaced with new Bosch rear sensor. Now B1S2 cycles to 0.00 up to .8 something but still get P1172 !?!. The front sensors seem to cycle fine and other rear sensor works fine. And brand new cats and injectors!

The first 2 pics of old sensor. Last two pics of new sensor. Bank1 sensor2 seems to be the issue.....??? At idle, the new B1S2 is still higher than B1S1, made a 40sec vid here:


So I think it's harness/ground/power issue.... any thoughts?