Review on Equus 8366 Ratio Gauge Aluminum by Michael Caste

I purchased and had this item (2" Air/Fuel Ratio Sensor - 8000 Series) from Revain.com last month finally got the opportunity to install it today on my machine. I followed the instructions in the documentation that came with the pressure gauge exactly, but I ran into a problem. My car only has one oxygen sensor so I used a large spade connector to connect it. The manual says this should cause both sides of the display to light up in the same order. Unfortunately only the right side moves up and down as the air/fuel ratio changes. The left indicator remains at full power (upper yellow indicator). I tried connecting the terminal to just one pin on the back of the sensor and nothing changed (only the right side moved, the left display stayed full rich). The gauges (left and right) stayed yellow at the top (rich gauge). This leads me to suspect that the sensor is defective and is even in the original packaging. I feel like this is something that should be replaced for free for me and would like to know how to proceed. I am currently using this in a single oxygen sensor configuration, but plan to use it with two sensors very soon, which would not be possible if only one side of the meter was working. This is my fourth Equus caliber on this car alone and so far I haven't had any issues. I contacted Equus and they informed me that I would need to ship the item back to them in the United States at my own shipping cost. I personally think this is unreasonable and would like to have a replacement sensor sent to me free of charge.