Originally Posted by hutch959
cool... your widband helped you find an issue.
and yes, mine is mounted about 3ft from the turbo (suggested by my tuner) and it reads about .4 lower than the stock sensor.
If your stock sensor is in the stock location (below the up-pipe) then the discrepancy may be due to the high pressure in that area. That's the main reason the stocker is insufficient for tuning.
Although I thought that was supposed to make the stocker read too rich... not really sure though.