Digital Air Fuel Ratio Gauge 52mm | Narrowband O2 Sensor for 12V Car Voltmeter 2 in 1

Monitor your engine's air-fuel mixture and battery voltage with this 52mm digital gauge. It combines an AFR display and a voltmeter in one compact unit, giving you two critical readings without taking up extra dashboard space. Designed for 12V gasoline vehicles, this gauge helps you keep your engine running efficiently.

This gauge uses a narrowband O2 sensor to measure the air-fuel ratio. The data is shown on a clear digital display, so you can see at a glance if your engine is running rich or lean. The built-in voltmeter also lets you track your battery's health, helping you spot charging system issues early.

The housing has a black finish and a racing-inspired look that fits well in most dashboards. It is built to fit standard 52mm gauge pods or holders. Whether you are tuning your car, monitoring a project vehicle, or just want more information about your engine's performance, this gauge provides the data you need.

Installation requires connecting the gauge and sensor to your vehicle's 12V system. The sensor wires are clearly labeled for heater, signal, and ground connections. Please check the included wiring diagram and your vehicle's compatibility before installation. The gauge cup or pod is not included and must be purchased separately.

Key Features and Benefits

- 2-in-1 design that combines an air-fuel ratio gauge and a voltmeter, saving dashboard space and providing two essential readings

• 52mm diameter housing that fits standard gauge pods and holders, making installation straightforward

• Narrowband O2 sensor that provides accurate air-fuel ratio readings, helping you tune and monitor engine performance

• Digital display that shows clear, easy-to-read numbers, so you can check your engine status at a glance

• Racing-inspired black housing that adds a sporty look to your dashboard or gauge cluster

• 12V DC operation that works with most gasoline vehicles, including cars, trucks, and motorcycles

Who Is This For

- Car enthusiasts who want to monitor their engine's air-fuel mixture while tuning or driving

• DIY mechanics working on project cars or trucks who need a reliable gauge for engine diagnostics

• Motorcycle owners looking to add a digital AFR and voltmeter to their handlebar or dash setup

• Anyone with a 12V gasoline vehicle who wants to keep an eye on battery voltage and fuel mixture

Usage Scenario

Mark had just finished rebuilding the carburetor on his classic pickup truck. He needed to make sure the air-fuel mixture was set correctly to avoid a rough idle or poor fuel economy. He installed this 52mm gauge in a spare dash pod, connected the O2 sensor to the exhaust, and turned the key. The digital display showed him the AFR reading in real time. He adjusted the carburetor until the gauge showed a balanced mixture. Now he drives with confidence, knowing his engine is running right.

Micro Comparison

Some gauges only show air-fuel ratio or voltage, but this unit gives you both in a single 52mm housing. That means you use one gauge pod instead of two, keeping your dashboard cleaner. The narrowband sensor is a practical choice for most street-driven cars and trucks where general mixture monitoring is the goal.

Specifications

- Material: Plastic shell

• Diameter: 52 mm / 2 in

• Voltage: DC 12V

• Color: Black

• Item Weight: 400 g / 14.1 oz

Please allow 1-3 cm / 0.4-1.2 in difference due to manual measurement.

Package Includes

Choose your package option:

• Package A: 1x Air Fuel Ratio Gauge

• Package B: 1x Sensor

• Package C: 1x Air Fuel Ratio Gauge + 1x Sensor

Note: The gauge cup or pod is not included and must be purchased separately.

Why You Will Love It

You get two important engine readings from one gauge, which simplifies your dashboard and your wiring. The digital display is easy to read even in bright light. It gives you the feedback you need to keep your engine running smoothly and catch problems before they get worse.

Questions and Answers

Question: Will this gauge work with a diesel engine?

Answer: This gauge is designed for 12V gasoline engines. It uses a narrowband O2 sensor, which is not suitable for diesel applications.

Question: Does the gauge come with the mounting cup or pod?

Answer: No, the gauge cup or pod is not included. You need to purchase a standard 52mm gauge pod separately.

Question: Can I use this gauge on a 24V vehicle?

Answer: No, this gauge is designed for 12V DC systems only. Using it on a 24V system may damage the unit.

Question: How do I connect the sensor wires?

Answer: The white wires are for the heater (positive and negative). The black wire is the signal line, and the gray wire is the signal ground. Please refer to the included wiring diagram for full details.

Question: Is this gauge compatible with a wideband O2 sensor?

Answer: No, this gauge is designed to work with a narrowband O2 sensor only. A wideband sensor will not provide correct readings.