Top Picks For Oxygen Sensor Related Parts

Today, modern vehicles are equipped with advanced electronics and sensors that allow the engine to function optimally for maximum performance. The oxygen sensor, also known as the lambda sensor, is an important component in vehicles today that determines the amount of unused oxygen in the exhaust. This data collected by the sensor is transmitted to the Electronic Control Module (ECM), which allows it to determine if the mixture is running lean (more air and less fuel) or rich (more fuel and less air). The ECM tries to adjust the air-fuel mixture and bring it close to an ideal, which helps in reducing emissions, increasing fuel efficiency and power. The oxygen sensor is located just before the catalytic converter and helps in maintaining a proper air-fuel mixture, which consequently allows for proper treatment of the exhaust gases in the catalytic converter. This oxygen sensor, situated before the catalytic converter, is called an upstream oxygen sensor. Some vehicles today are also equipped with a downstream oxygen sensor, situated after the converter, which helps in monitoring the quantity of oxygen in the exhaust gas flowing out of the catalytic converter. The ECM compares the data between the two sensors to measure the efficiency of the converter.

Most of the vehicles run on hydrocarbon fuels like diesel or gasoline, which produce a lot of emissions when burnt in an engine. These emissions are harmful to the environment and human health, as they comprise pollutants like nitrogen oxide, carbon monoxide, and hydrocarbons. Therefore, vehicles are equipped with catalytic converters which are engineered to reduce emissions by converting these harmful gases into non-toxic gases like carbon dioxide and water vapor. The converter carries out reduction and oxidation (redox) reactions in the presence of precious metals like rhodium, palladium, and platinum that act as catalysts. Catalytic converters are of two types: two-way and three-way catalytic converters. A two-way catalytic converter reduces only carbon monoxide and hydrocarbon pollutants, whereas a three-way catalytic converter treats carbon monoxide, hydrocarbons, and nitrogen oxide emissions as well.

Catalytic converters are designed to last a long time, however, they may have to be replaced at some point in the vehicle's lifetime, which depends on various factors. With time, as your vehicle ages, the residue deposit leftover by the exhaust gases clogs the converter. You may also have to replace your converter if it incurs any physical damage. Failing an emission test is the first sign of a bad converter along with other symptoms like check engine light is on, sudden drop in fuel economy, and misfiring. A bad catalytic converter can also lead to a foul smell like rotten eggs, which is caused due to sulfur coming out from the exhaust. Sluggish engine performance and rattling sounds due to a damaged converter also call for the need to get your converter checked and replaced.

The Mass Air Flow Sensor (MAF) is an important component used in modern electronic fuel injection (EFI) systems and is installed between the air filter and the intake manifold. The MAF sensor measures the amount of air entering the engine and sends the data to the Electronic Control Module (ECM). This helps in regulating the amount of fuel supply according to the air mass to ensure a balanced air-fuel mixture. The role of MAF sensors is very important because density and the mass of the air change with the change in altitude, temperature, and forced inductions as well. These sensors help in determining the accurate quantity of air intake in each cylinder. Vane airflow meter and Hotwire airflow sensor are two types of MAF sensors used in vehicles. However, the most common type of MAF sensor used in cars today is the hot-wire type because it has a quick response time, is smaller in size, and is very durable.

A bad Mass Air Flow (MAF) sensor won't be able to calculate the amount of airflow, which can make the air-fuel mixture rich or lean, leading to problems like detonation in the combustion chamber. Other symptoms that come with a bad MAF sensor include poor driveability, engine jerks during acceleration, and bad engine idling. Several contaminants like dirt or oil can also deposit on the sensing wire, allowing the sensor to malfunction. Additionally, a faulty MAF sensor can also light up the check engine light on the dashboard. Often the solution of a malfunctioning sensor may be as simple as cleaning the wires, but it is a good idea to get your sensor checked for damage and get it replaced if you notice the aforementioned symptoms. 

There are several sensors in an engine today that help in the overall functionality of the vehicle. Some sensors read oxygen levels, air density, and temperature, etc. Knock sensors, on the other hand, keep a tap on unplanned vibrations and sound levels that occur within a combustion chamber due to uncontrolled ignition timing or air-fuel mixture explosion. When the spark ignites the compressed air-fuel mixture in an engine, a flame front moves along the chamber, combusting a whole mixture. Often due to high temperature and pressures, some of the air-fuel mixtures ignite on their own or detonate, which sends another wave across the combustion chamber against the original flame front. This results in a sudden spike in vibrations and noise and can also lead to major damage to an engine. Therefore, a knock sensor is used to pick up vibrations and sounds from the engine block so the ECM can regulate the ignition timing accordingly. The knock sensor is directly attached to the engine block and is made using piezoelectric ceramic or elements that convert a mechanical effect, like vibrations, into electrical signals.

The most common reason for a knock sensor to fail prematurely is continued exposure to harsh conditions and other physical damages like rust, short circuit, wiring damage, improper mounting, or mechanical injury while performing vehicle maintenance. However, there are other underlying reasons which can cause the sensor to fail. Excessive heat, bad fuel, and faulty spark plugs can lead to abnormal knocking, which can make an already bad sensor give up. Furthermore, any kind of accretion, like carbon build-up on the sensor, can also cause the knock sensor to fail. A bad knock sensor can exhibit symptoms like poor acceleration, decreased engine performance, knocking or pinging noises, and most importantly, will cause the check engine light on your console to come up. If you notice similar symptoms on your vehicle, you should verify the sensor's wiring connections, look for any damage and read out the fault codes related to the sensor and get it replaced.

The Electronic Control Module (ECM) is a computer with a pre-programmed chip that is used to operate the engine using the data provided by the sensors. Modern vehicles today use several electronic control units that control various functions like engine, power steering control, HVAC systems, door locks, airbags, emergency braking, etc. Some vehicles have more than one control unit for different features, whereas some vehicles have a single control module to control everything. Electronic control modules can be of various types depending on the tasks they perform and some of these are known as Brake Control Module (BCM), Transmission Control Module (TCM), Suspension Control Module (SCM), etc. The electronic control module also plays a bigger role in the overall functioning and performance of the engine by monitoring the data from the sensors that include various parameters like air-fuel mixture ratio, coolant temperature, manifold air pressure, throttle position, crankshaft position, knock, airflow mass, vehicle speed, etc.

A faulty Electronic Module (ECM) can pose some great problems to your vehicle because it will not only affect the performance of the vehicle but can also lead to a complete breakdown. If your ECM fails completely, your car won't start at all because it controls the ignition. The most common sign of a bad engine control module is a check engine light and an erratic engine. This can be accompanied by increased fuel consumption, starting problems, and a significant drop in engine performance. A damaged ECM can also lead to problems while shifting gears in an automatic transmission or sudden jerks while driving. If you notice these symptoms and suspect that your ECM might be bad, you should immediately get your ECM checked and replaced.