i switched lsu 4.2,and readings are back normal... i get even 8.0 so this is a hint for next people having same problems... don't know the cause of such quick degeration of the sensor...

this is my idle... pwm valve programmed as warmup pwm idle, because i'm still working with ve maps, so can't use closed loop idle, but checked and it works perfectly
m104 running on megasquirt III v3.0 with strange innovate lc1 readings.... - YouTube