AEM UGEO wideband

[redSRpilot]

Hey guys,
i have a AEM wideband O2 on my sr20det connected stand alone. Straight from my sensor to the gauge. Power wire to an add-a-line connected to an ignition fuse. Ground wire bolted to a spot on the A frame. Car runs pretty good but I'm getting about a 1.0 difference in my A/F readings when my headlights or electric fans are on compared to when they are off.. I'm assuming it's some sort of ground issue but have checked all grounds multiple times. Anyone have this issue? Would it make any difference if I ran my ground to the intake manifold? Maybe get a yellow top battery?