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Your Car Failed Emissions Testing. What Next?

Emissions inspections are tests conducted on vehicles to ensure they do not produce pollutants at a higher than acceptable rate. Every vehicle on the road, with the exception of motorcycles and historic vehicles, is required to pass these tests in order to register their vehicles and legally drive in several states throughout the U.S. Unfortunately, many vehicles fail their tests for a variety of reasons.

Why Cars Fail Emissions Testing

There are many common reasons for vehicles to fail their emissions inspections. If your car failed, it may have been one of these problems:

  • Faulty oxygen sensor – This part makes sure there is a proper amount of oxygen in the exhaust gas. When left unchecked, it can cause a loss of acceleration power and increased toxic emissions.
  • Vacuum leaks – Anything that leaks between the MAF air flow sensor and intake manifold including anything vacuum operated.
  • Error in Evaporative emission control system – Leaks in the EVAP system, faulty gas caps, and defective purge valves can cause this error to register.
  • Air injection system malfunction – The engine may not be able to effectively control hydrocarbon and carbon monoxide emission levels in older vehicles, OBD-2 systems on newer models only at a cold start.
  • Rich Fuel – This may be due to a weak ignition, leaky injections, weak 02 sensors, failed mass air flow sensor, excessive fuel pressure, or failed fuel pressure regulator.

What Repairs Your Car May Need

Many of these problems can be resolved rather quickly. A new fuel cap, for example, can often solve your EVAP error. In some cases, the cap may just not be sealed tightly. Unfortunately, in other cases, more extensive repairs may be necessary. A faulty oxygen sensor may require more work but is often not an extensive repair depending on your vehicle. Locating and fixing vacuum leaks can be more labor-intensive. If your air injection system is malfunctioning, it may involve replacing air pumps, check valves, inlet hoses, and fuses. Rich fuel can be brought down to normal levels by tuning or replacing your carburetor. In each case, an inspection and diagnosis must first be made on older cars. Newer cars with OBD-1 & OBD-2 systems may require a diagnosis for further prognosis.

Why Do Emissions Testing Matter?

Why would you spend so much time and money in order to pass a simple test? The testing is there to ensure that cars do not fill the environment with harmful pollutants, which could cause significant health consequences for both people and animals alike. It has the added benefit of alerting you to potential issues with your vehicle before they ever become a problem.