Skip to content

What are the Causes of Air Pollution Test Failed?

What are the Causes of Air Pollution Test Failed

What are the Causes of Air Pollution Test Failed –┬ástate and federal governments have placed limits of harmful gases emitted by vehicles? An emissions test, also known as pollution test will measure the hydrocarbons, carbon monoxide, carbon dioxide and oxides of nitrogen emissions levels. There are several common causes that lead to a test vehicle in the absence of pollution. Check Engine Light
If the light on the check engine light or malfunction indicator is illuminated, it will result in an automatic test failure pollution. If the light is on, take your vehicle to a repair shop so that they can diagnose the problem.

What are the Causes of Air Pollution Test Failed


the engine of your old car breathes smoke from oil pans and other automobile components. These gases make their way through combustion and contaminate the engine oil. Change the oil regularly will eliminate these gases and allows your vehicle to pass inspection.

Low tire pressure

Inflate your tires before a pollution inspection. During the pollution test, a technician may have to drive your vehicle on a dynamometer. Inflated tires improve the stability and accuracy of this part of the exam. In addition, global emissions of your vehicle are improved, allowing the engine to maintain a constant load.

Gas diagnose failure

Read the smoke failure report to evaluate which gas caused the failure. A failure HC results from incomplete combustion. If you had a HC failure, the most common causes are used spark plugs, bad spark plug wires, distributor cap or worn rotor point of improper ignition, vacuum leaks or engine mechanical failure. A CO failure results from a mixture of fuel and over-rich air is usually caused by a dead air injection system, an oxygen sensor is defective, a gun leaking fuel or defective, a restricted air filter, a leak vacuum incorrect operation of the multiple absolute pressure sensor, an air mass defective or air flow sensor, a faulty catalytic converter, a defective thermostat, contaminated fuel oil or a fuel evaporation system malfunction in the purge valve. Finally, a failure is NOx combustion temperatures run too high. The most common causes of a NOx failure is a malfunction in the cooling system, a more advanced ignition point, a mixture of air over-lean fuel or a dead recirculation gas system.