The automobile industry is working tirelessly to improve its models’ fuel efficiency and carbon footprint.
From developing battery-powered vehicles to using multiple sensors for tracking fuel levels, several steps have been implemented so far.
The lambda sensor is one such considerable element in most modern-day auto models. It has become one of the most significant sensors for every engine as it continuously monitors the oxygen level in the exhaust gases.
Doing so helps optimize the overall air-fuel mixture and reduces the emission levels of CO2. Since it is a key component of a car’s engine, you should be aware of its working, faulty symptoms, and other relevant details.
Only then you can ensure your car’s health is at optimal levels with no issues with the current emission rates.
Also, you can easily remain compliant with pollution control regulations and standards. That being said, we have articulated a detailed guide on what lambda sensor is, its working, benefits, and many other aspects.
It will give you a detailed picture of this key automobile component and help you understand its importance.
Table of Contents
Lambda Sensor: A Brief Introduction
Also known as an O2 sensor, it measures the volume of oxygen in the exhaust gases. As a result, the internal combustion engine can easily optimize the air-to-fuel ratio and maintain the desired limit for better emission control.
One or more sensors can be present depending on the automobile’s requirements. They are usually located before and after the catalytic converters in the exhaust system.
Hence, they can accurately measure the engine’s performance and optimize the same for better fuel economy and lower carbon footprint.
Working of a Lambda Sensor: How Does It Control the O2 Levels?
Understanding the detailed mechanism of the lambda sensor will help you acknowledge its importance in modern-day vehicles. That’s why below we have explained a brief guide on the same.
- Sensing the oxygen concentration: The sensor will detect the volume of oxygen in the exhaust gases before they are emitted from the vehicles accurately. Most components are calibrated to take precise measurements for optimal functioning.
- Data transmission: The measured oxygen concentration data is then transmitted to the ECU or the Engine Control Unit of the vehicle.
- Fuel-gas mixture adjustment: Based on the data received, the ECU will adjust the fuel and gas mixture.
- Lean mixture (higher oxygen concentration but lower fuel volume): More fuel is injected to increase its delivery.
- Rich mixture (lower oxygen volume but higher fuel concentration): Fuel injection is reduced to maintain the balance.
- Optimizing for stoichiometry ratio: The main purpose of the lambda sensor and the ECU unit is to work together to maintain the stoichiometry balance. In other words, they ensure for every 1 part of fuel, 14.7 parts of oxygen are present in the internal combustion engine.
Types of Lambda Sensors Used in Automotives
Zirconia Lambda Sensor
- Primarily made up of Zirconium dioxide that generates a voltage once exposed to oxygen gas.
- Indicates if the air-to-fuel mixture is lean or rich with no accurate measurement.
- Has a voltage range between 0.1V (indicating a lean mixture) and 0.9V (meaning a rich mixture).
- Mostly used in older car models for regular adjustments of the AFR value.
- Highly affordable and easily available in the market.
Wideband Lambda Sensor
- Although zirconium dioxide is used, an additional reference cell is included in the setup for more precise AFR measurements.
- Has a linear voltage function operating within a range of 2V to 5V.
- Produces a highly accurate AFR measurement within a broad spectrum, ranging between 10:1 and 20:1.
- Best-suited for high-performance and turbocharged engines.
- Aftermarket use will require numerous specific controllers for the desired precision.
Titania Lambda Sensor
- Made up of titanium dioxide that changes the internal resistance based on the sensed oxygen content in the exhaust gases.
- In lean mixtures, there is a decline in the electrical resistance, whereas, for rich content, it spikes up.
- Linear voltage output ranges between 0V and 5V.
- Has a faster response time compared to the lambda sensors having zirconium dioxide.
- Doesn’t offer much accuracy in AFR measurements and hence is used in older European vehicles.
Why Using a Lambda Sensor is Important in Vehicles?
Optimizes Air-to-Fuel Ratio (AFR Ratio)
- The AFR value of a certain vehicle represents the fuel economy and the overall engine efficiency.
- A lambda sensor helps determine this ratio to ensure the ECU can maintain the stoichiometric value with ease.
- In case the mixture is lean, the ECU will inject more fuel to balance the ratio.
- On the contrary, if the sensor detects a rich mixture with lower oxygen concentration, fuel injection will be reduced.
Reduces Harmful Emission
- Thanks to the sensor’s real-time oxygen measuring capability, the catalytic converter can work more efficiently.
- Emission of harmful gases can be reduced, like:
- Carbon monoxide
- Hydrocarbons
- Nitrogen oxide
- Vehicles can meet the regulatory standards and compliances for emission controls like the Euro 6 standards and the EPA regulations.
Improves Fuel Efficiency
- The lambda sensor detects the fuel level accurately and determine if the volume is to be increased or decreased to achieve the stoichiometry.
- It helps reduce fuel wastage, thereby improving the overall miles per gallon rate of the vehicle.
- If the sensor was not in place, the engine would consume more fuel according to the preset levels regardless of the AFR value.
Enhances Engine Performance
- As the lambda sensor balances the AFR ratio, the internal combustion engine can work more efficiently.
- Issues like engine misfires, rough idling, and others can be prevented easily.
- With the correct air-to-fuel mixture, the transmission system will function better, thereby delivering higher power for a smoother acceleration.
- Engines won’t suffer due to overheating since the ECU will balance the lean mixture based on the data received from the sensor.
Wrap Up!
Using the lambda sensor in the car brings numerous benefits to the table, like enhanced fuel economy and improved engine performance.
However, you should be on the lookout for any symptom that could indicate a faulty sensor. If it is not addressed immediately, your car’s fuel economy and the engine’s health will be put at stake.
