4 Causes of a Failed Emissions Test

4 Causes of a Failed Emissions Test

4 Causes of a Failed Emissions TestNearly all vehicles must go through emissions testing on a regular basis in order to be legally licensed. If your car or truck has ever failed an emissions test you understand that it can be a stressful situation, requiring a trip to the mechanic to have the problem attempted to be repaired. But some of the most common issues that cause emissions test failure are generally less expensive than what you are required to spend "trying" to repair whatever issue is at hand. These are four of the most common reasons a vehicle will not pass an emissions test.

Failing EVAP System

The Evaporative Emission Control System (EVAP) prevents gasoline vapors from being released into the air. This system will not be able to function correctly if there is a leak in a connected vacuum hose or if there is a cracked, broken or loose gas cap.

Bad O2 Sensor

If your oxygen sensor malfunctions it can not properly monitor exhaust fumes, which will cause several problems for your vehicle, including a major decrease in fuel efficiency. However, the reasons this causes your vehicle to fail the test is that it can increase the hazardous fumes within your car's exhaust.

Rich Fuel Mixture

If high levels of carbon monoxide are detected in the emissions test your vehicle will not pass, an issue often associated with the burning of too much gasoline. This can happen due to a faulty O2 sensor or Mass Air Flow sensor, or because of leaking fuel injectors.

Bad Fuel Metering

Your vehicle monitors fuel use to ensure that a correct air-fuel mixture is created to keep the engine running smooth. If the computerized engine control or computer aided fuel injection unit fails or malfunctions the monitoring will be incorrect, which will cause the vehicle to fail emissions.

If your car is due for an emissions test or needs emission test repair in Lancaster head to McKonly's Garage. The auto repair technicians at our family owned shop will ensure that your vehicle is safe and legal to drive. To schedule an appointment for full service auto repair in Lancaster don't hesitate to call (717) 208-8210 today.

McKonly's Garage Blog

Written and Published By MORBiZ

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