Wideband Reading High
 

I just got all my gauges working and my Wideband gauge is reading really high even after calibration. I have a prosport EVO series gauge on my 94 RX7 and the O2 sensor is about 34 inches back from exhaust port. 36 inches was recommended by prosport for a turbo.
So my gauge at idle is reading between 17.4 to 19.8 and never steady. RPM's are around 1100 or so. When i hit the pedal the gauge reads around 12 or so.

Is this normal or a faulty gauge/sensor?
Or no tune.....I do have a stock ECU with downpipe, catback, custom intake, NGK plugs. And i think that is about it.

sensor calibration , exhaust pipe earth , and possible exhaust leak before the sender

What is exhaust pipe earth?

There's a ground wire on the exhaust pipe, it bolts to the bottom of the car.