? for dmm user's, monitoring lean burn

[rlprlp1]

I hooked up the dmm to monitor lean burn. Currently the highest positive reading im getting is .41 and the lowest is -.88. This 02 sensor (for the 92 vx, 5 wire) i purchased from oxygensensor.net. Its the one with the blue wire instead of the red. Anyway, i put the old one back in, the one that came with the car, and im getting readings from -.88 to 1.04. Does this sound normal, does it sound like the older one will allow the car to run more lean? I wont know if the mpgs changed till my next fill up. Just wondering what thoughts are. Thanks in advance. Having the dmm hooked up did allow me to keep the car in lean burn longer, and my milage came up some.