ok weird situation... Im currently replacing front O2 sensor on passenger USA side as I was getting a reading of about .035 constantly with minor fluctuations to .050... then replaced that O2 and all went to normal quick switching.. then day 2 that side went to 0.00 and stayed that way.. I took off the connector and cleaned it again and BAM did not change... was pissed... then unplugged battery for hr or so and pugged back in... same... no change 0.00 so now pissed and confused... then next day... it started switching perfect but now other side was staying around .445 for the day.. maybe small fluctuations... still was getting codes 134 135 155 .... now... everything for last few days has switched nicely both O2 maybe it was remapping? however I noticed... after cleaning codes when I start up disco and SAI pump comes on as usual... I get 0.00 then codes set but then starts switching normally once SAI goes off in a few seconds... is this leading back to the SAI solenoid relay or switch causing these readings? hmmm or could MAF be involved here? no MAF codes but of could I have ultra gauge and can detail MAF readings if necessary for helping me

 

I also noticed that when Im going down a hill in normal city driving and let off gas pedal and allow engine to slow me down some or regulate speed the same Passenger side USA O2 sensor goes to 0.00 then once Im back to using gas it starts witching again as normal...