DRAGON 52mm Air Fuel Ratio Gauge With Narrowband O2 Oxygen Sensor Car Gauge Digital Display Fit for 12V Car 0258006028 1.After the digital meter is connected to the power supply, it will read the voltage for 1 minute and then switch to the air-fuel ratio. 2.Air-fuel ratio gauge is suitable for 12V gasoline vehicles 3.The oxygen sensor is suitable for Geely Emgrand Citroen Fiat PEUGEOT Oxygen Sensor Specification: Working Voltage: DC12V Signal Line Voltage: 0-1V Spiral: M18*1.5 Use Wrench: 22mm Output Voltage: Maximum value 900mv/ minimum value 50mv. Response time: (600mV-300mV) 100ms. Response time: (300mV -600mV) 100ms. Starting time: 10s Heating resistance: 8.5~9.5 Internal resistance: 200~300 Package included: 1* Air Fuel AFR Gauge 1* Narrowband Oxygen Sensor 1* English Manual(Only teach how to install the gauge,but do not teach how to install the O2 sensor,thanks) Connection : The white line is at heater ab Black line signal line C, gray line signal ground D The green wire of the instrument is connected with the black wire of the sensor. The gray line is connected to the negative pole of the battery. One white wire connect with the car shell or battery negative pole. Another white wire connect to the ACC line of ignition switch The white line is the heater and does not distinguish between positive and negative electrodes About the air fuel gauge, please see the installation instructions. Attention: If you need the sensor and the gauge , please choose the item of sensor and gauge together. Note: 1.Highly Recommended professional installation,do not teach you how to connect the O2 Oxygen sensor. 2.This kit is not a universal kit, please confirm whether this oxygen sensor is suitable for your car before buying, thank you!