Category: Emissions Systems

car emission problems

4 Emission System Problems That You Should Be Aware Of

Emissions Systems

When it comes to our cars, we all want them to run as smoothly and efficiently as possible. And one of the most important systems that help make this happen is the emission system. This system is responsible for getting rid of harmful toxins that are released when the car is running. Unfortunately, this system can malfunction in a number of ways, causing the toxins to be released into the air that you and your passengers breathe. That doesn’t only cause problems for your vehicle, it could also lead you to fail a car emission test that’s a requirement for most states.

That’s why it’s important to be aware of the most common emission system problems so that you can get your car fixed as soon as possible if something goes wrong. Here are four of the most common issues:

Faulty Oxygen Sensor

One of the most important components of the emission system is the oxygen sensor. This sensor monitors the amount of oxygen in the exhaust and sends signals to the engine control unit (ECU) to make adjustments accordingly. If the oxygen sensor is not working properly, it can cause the engine to run lean or rich, which can lead to increased emissions.

Catalytic Converter Issues

Another common problem that can lead to excess emissions is a faulty catalytic converter. The key function of the catalytic converter is to reduce harmful emissions, but if this component isn’t working properly, then it won’t be able to do its job effectively. This will lead your car to release more harmful toxins into the air.

Blockage in the Exhaust System

If there are blockages or restrictions in your car’s exhaust system, such as carbon build-up, your engine may not be able to expel all of its waste gases efficiently. This can cause an increase in harmful emissions and decrease fuel economy.

Faulty Mass Airflow Sensor

Finally, one other issue that can lead to increased emissions is a faulty mass airflow sensor (MAF). This sensor measures how much air enters the engine so that the ECU can adjust the amount of fuel that’s mixed with it. If there is a problem with this sensor, it will be unable to measure and send signals properly, resulting in excess emissions.

If you notice that your car has any of these issues or other problems with its emission system, it’s important to get them fixed as soon as possible. This will help ensure that your car runs smoothly and efficiently while also protecting the environment from harmful toxins. And by taking care of these problems early on, you’ll save yourself money in the long run by avoiding costly repairs down the road.

Vehicle Air Pollution

Ever wonder How Your Car Emission System Works?

Car Diy RepairsEmissions Systems

Source: Wonder How Your Car Emission System Works? Here Is How

Easy step by step guide on how automotive emissions systems work, though appearances may vary, the process is the same for most vehicles.









Your Car’s Emissions Process

Step 1 – The vehicle computer is responsible for the emissions produced by the internal combustion engine it controls. By using many sensors such as an oxygenor mass air flow, which provide feedback data for the computer to analyze and adjust engine emissions, which are controlled to within manufacturer specifications.

Step 2 – The exhaust system oxygen sensor is designed to sense the amount of oxygen in the exhaust system and send feedback data to the computer.

Step 3 – An EVAP (evaporative emission) solenoid is used to purge raw gas vapor from the fuel tank as to not allow these fumes to enter the atmosphere.

Step 4 – An electronic throttle actuator is designed to move the throttle plate only when the engine can utilize the fuel being consumed. This control helps unneeded emissions when a driver over advances the throttle pedal.

Step 5 – A catalytic converter is utilized to expend un-burnt fuel in the exhaust system. The unit is heated by exhaust gases as thermo reaction heats up to achieve the design goal of lowering exhaust emissions. By using primary and secondary oxygen sensors the efficiency of the catalytic converter is monitored. An electric air pump is sometimes used to help heat up the catalytic converters to optimize efficiency.

Step 6 – The mass air flow sensor monitors airflow that enters the engine by measuring resistance across a hot wire that is cooled while various amounts of air pass over it. This feedback data trims the computers adjustments to further help clean emission output.

Step 7 – The gas cap seals the liquid and fumed gases from escaping the fuel tank. This cap is designed with an automatic tightening mechanism to support a minimum tension the cap must be installed at.

Step 8 – An EGR valve (exhaust gas recirculation) is use to allow engine exhaust to enter the intake manifold of the engine which cools combustion temperatures and lowers emissions.

Helpful Information

Emission control systems have been incorporated into automobiles to prevent pollution by limiting the amount of partially burned and evaporated gases into the atmosphere. These systems have been efficient in reducing the air pollution caused by automobiles to a large extent. Increased engine efficiency and lighter vehicle construction has also contributed to helping reduce emissions. The different aspects of emissions are tailpipe emissions, life cycle emissions and evaporative fuel emissions.Unspent fuel vapors are known as the main contributors to air pollution. These omitted gases consist of carbon monoxide, hydrocarbons, carbon dioxide and nitrogen oxide.

Lifecycle emissions are byproducts which are released into the environment during the manufacturing, maintenance and disposal of the vehicle. These products include volatile solvents such as auto paint and lubricants, manufacturing plant waste, petroleum, heavy metals and many more. The name “catalytic converter” was derived from the operation the device performs. A catalyst material converts partially burned gases to completely burned gases.


Automobiles were first manufactured with exhaust emissions control systems in 1966. Since then, technology has undergone several advancements that have increased the efficiency of the internal combustion engine. Older emission control systems inject air into the exhaust manifold which are known as, air injection reactor (AIR.) The catalytic converter was developed in the early 1970’s when severe air pollution was widespread and was made mandatory by the US government in 1976. An EGR valve is used is to lower KNOX (NO2) gases which occur when the combustion chamber when temperature reaches over 3500°.

Tailpipe emission are measured in parts per million or PPM. The first smog emission test was conducted in the mid 1980’s. Restrictions in smog laws came later which ushered in the use of a dynamo-meter so vehicles could be tested as if they were being driven, the number of gases measured also increased.


Article first published 2016-02-04

Source: Wonder How Your Car Emission System Works? Here Is How

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TerrysArticles is brought to you by ME!, traveling Mechanic Terry Wade, I’m do my darndest to update the site with the best quality articles and news available on the internet and elsewhere to help you diagnose and fix your vehicle yourself.

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