Are you running really lean?
Try patting the gas a little at idle, just enough to get it to rev a tiny and drop off suddenly, You should be able to get it to swing into the readable AFR, if so, you are crazy lean.
It's not plugged in? That's your problem.
What do you have done to your car and what are you driving?
Does it give you 2-3 letter/number combinations when the gauge turns on?
Yes it does.
It's in your sig in the top but not the rest of them. What tune do you have?
"Halfassery" 2000 GTP, L67 Engine and Tranny,ZZP 3" down pipe, Triple Gauge A-Pillar Pod, 10.5 mm Plug wires, polly dogbone bushings, polly engine mounts, modded fuel rail, #80 injectors, manual boost controller, front plog, turbo crossover and oil feed and return system.TaiL wastgate and BOV.6262 Billet Wheel Turbo and other stuff..........