52mm Narrowband Air Fuel Ratio Gauge Kit | 12V Car O2 Sensor Voltmeter

Key Features

• Stepper Motor Movement — The stepper motor moves the needle precisely and gives accurate readings once powered on.
• Narrowband O2 Sensor — A narrowband O2 sensor is included and connects to the gauge for a complete monitoring setup.
• Universal 52mm Fit — The 52mm diameter fits standard gauge pods, panels, and mounting cups.
• 12V Vehicle Use — It works with 12V cars, trucks, and gasoline engines.
• Black Plastic Housing — The black plastic housing matches most interior trims and gives a clean look.

Product Specifications

• Dimensions: 52 mm (2.05 in)
• Weight: 400g / 14.1 oz
• Power: DC 12V
• Material: Plastic Shell
• Color: Black
• Placement on Vehicle: Front
• Package Contents: 1x Air Fuel Ratio Gauge; 1x Narrowband O2 Sensor

What It Is / How It Works

This 52mm narrowband air fuel ratio gauge kit is a dashboard gauge with an O2 sensor that shows the air-fuel mixture of a 12V engine in real time.

Who It's For / Use Cases

Air fuel ratio gauges suit car enthusiasts who want to watch the air-fuel mixture while tuning an engine, DIY mechanics adding gauges to a dashboard, and truck owners who track fuel mixture to manage fuel economy. They also fit people building a multi-gauge setup who want air-fuel monitoring alongside boost, temperature, or pressure readings.

How to Use / Care

1. Use the gauge as a standalone monitoring tool to watch your engine's air-fuel mixture in real time.
2. Pair it with other gauges from the same series, such as a turbo boost, water temp, or oil pressure gauge, for a combined dashboard view.
3. Keep power connected to the gauge, because the stepper motor needs power to return the pointer to zero.
4. Install it in a dashboard pod or panel to see what the engine is doing, as one owner did with this air fuel ratio gauge.

How to Choose

Start with your vehicle's electrical system, since this gauge is built for a 12V DC system. Check that your oxygen sensor is narrowband, because this kit is designed for narrowband sensors only. Confirm you have a 52mm mounting space in a pod, panel, or cup, and buy a gauge cup separately if you do not already have one.

Frequently Asked Questions

Does this gauge work with a wideband O2 sensor?
No. This gauge is designed for narrowband O2 sensors only, and a wideband sensor will not work with this kit.

Is the gauge cup included?
No, the gauge cup is not included and must be purchased separately. The kit contains the gauge and a narrowband O2 sensor.

Why doesn't the needle return to zero when the car is off?
This gauge uses a stepper motor that needs power to return to zero. It is normal for the pointer to stay in place when the power is off.

Can I install this gauge in a motorcycle?
Yes, it fits motorcycles with a 12V electrical system and a 52mm mounting space.

What voltage does this gauge require?
It runs on a standard 12V DC electrical system, the type found in most cars and trucks.