An emissions test is a test conducted on vehicles to check for pollutant emissions formed by the engine of a car. There are usually specific standards a vehicle must pass to be cleared from the emissions test. Given that motor vehicles are among the top sources of air pollution, keeping tailpipe emissions at bay is crucial for improving air quality and reducing negative environmental impact. That’s exactly why the Pollution Control Board (PCB) prescribes strict emissions standards and why every Indian state conducts emissions tests to make sure vehicles meet those standards.
Emissions tests are designed at ensuring that the levels of toxic gases produced by vehicles on the road do not exceed the defined limits. These tests measure the volume of tailpipe emissions produced by car engines, in order to check whether a vehicle meets the regulations that restrict emissions of specific pollutants. They take in account the levels of nitrogen oxide (NOx), carbon monoxide (CO), particulate matter (PM), non-methane organic gases (NMOG), and formaldehyde (HCHO). Nevertheless, there are times when an engine fails this test. Further down are some of the common reasons for failing an emissions test.
If you are not sure where your vehicle stands? We’re taking a look at how these tests that are conducted and what the most common causes for failure are, so that you can have those issues fixed before your test. In many cases, car possessors or a mechanic can easily resolve the issues leading to a failed emissions test.
Possible reasons for failure
- Fuel metering out of specification. There are numerous factors that can cause a fuel metering of your vehicle to be out of specification. It may be due to a defective computerized engine control, carburetor, or fuel injection unit
- Faulty oxygen sensor. The oxygen sensor in a vehicle keeps a check on the amount of oxygen in the exhaust gas. A faulty or defective oxygen sensor is not unusual and can be caused by several things. A faulty oxygen sensor can lead to other problems including overheating, complex toxic emissions and loss of acceleration power
- Imperfect ignition system. This means that during an HC check, the analyzer senses high Hydrocarbons. If the vehicle is not appropriately maintained then expect to have an ignition system that is defective causing it to fail an emissions test. The most mutual causes of high HC are defective spark plugs wires, worn out spark plugs, over advanced ignition timing or a worn out distributor cap
- Leakages in the vehicle’s vacuum. Vacuum leaks are one more common cause for an emissions test failure. A vacuum leak is habitually caused by the MAP sensor not working properly. The MAP sensor measures the load of an inner combustion of the engine’s electronic control system.
- Rich oil mixture. High CO2levels are frequently caused by high carbon monoxide levels due to a weak ignition or a rich air/fuel mixture. There are several causes of a rich fuel mixture. A polluted oxygen sensor, leaky injectors, and excessive fuel pressure are some common causes of richness to the mixture
- Failure in the air injection system. The air injection system services reduce the emission of hydrocarbons and carbon monoxide of a car. This is done by compelling fresh air into the exhaust of the engine. If the air injection system is defective or malfunctions, the engine is not able to appropriately control the levels of hydrocarbons and carbon monoxide emission causing the car to emit high levels of these dangerous gases
- Faulty evaporative emission control system. EVAP or Evaporative Emission Control System prevents gasoline vapors from the fuel system and tank from being on the loose into the atmosphere. Some of the more common causes of a defective EVAP comprise leaks in the vacuum hoses and vents, defective purge valves, or faulty gas caps.
- Defective “check engine” light. From time to time, even if every other component that has to do with controlling your car’s emissions works correctly, you might still fail an emissions test as the “check engine” light itself is malfunctioning.
- Worn spark plugs. In the middle of other issues, worn spark plugs can also lead to increased emissions of gases. That is why you need to look at them regularly and replace them as necessary.
How Emissions Test Equipment Works:
Commonly, the equipment used for vehicle emissions testing varies but the overall performance and duty is the same.
In a smog check program, there are normally three types of vehicle inspections. The Acceleration Simulation (ASM) is done to check for the emission of hazardous gases like carbon monoxide. The On-Board Diagnostics (OBD) is the computer system in a vehicle that monitors the enactment and status of the ignition system and emission control equipment. TSI or Two-Speed Idle is used to test car model year 1995 and earlier for emission gases.
Every effort you can make to prepare your car for the test is certainly worth your while, if you want to keep your car on the road.
And since care causes most of the issues that result in test failure, it’s safe to say that simply taking proper care of your car and performing essential maintenance tasks regularly, such as exchanging the oil or cleaning and replacing the air filter, can go a long way. But before taking your car to the test, we commend having it inspected by a professional mechanic to learn for sure what specific parts need to be repaired or changed, so that you can pass the test with flying colors. Get authentic and 100% genuine parts online from Autokartz.com