Few Reasons Why Your Vehicle May Fail Emission Test

Nowadays emission test is mandatory for your vehicle at least twice in a year and it can really be a stressful experience in case your vehicle ever fails to clear the emission test.

In case, your vehicle fails to clear the emission test then you need to take to certain mechanic to get your vehicle properly repaired and checked. Luckily few of the problems that cause emission problems are not too difficult to fix without visiting Greg’s Japanese Auto.

Following are the five reasons why your vehicle may fail in the emission test.

  • Faulty 02 sensor

If the oxygen sensor becomes faulty then it may not be able to monitor exhaust fumes properly and this may result in few more issues for your vehicle which include reduction in power of engine or rough idle, and also drastic drop of fuel efficiency.

Bad oxygen sensor can increase toxicity of the emission of your vehicle.

  •  Rich fuel mixture

In case, there is very high presence of CO in the emission of your vehicle then it is likely that there must be excessive amount of burning of gasoline happening that is also called running rich.

Such condition can happen because of a faulty sensor for mass air flow or because of clogging, leaking or any otherwise malfunction type fuel injectors.

  • Improper fuel metering

All fuel usages are properly monitored to make sure that the exact amount of gasoline will be burned for creating smooth running engine.

In case, the engine controls or any fuel injection unit starts malfunctioning and as a result, fuel monitoring will provide incorrect result, which may also result in increased emissions and also a test failure.

  • EVAP system

There is an Evaporative Emission Control System known as EVAP, which can prevent the release of gas fumes from your vehicle into the natural atmosphere.

Such kind of system can often malfunction in case there is a sufficient leak in your vacuum hoses or the vents or because of either a broken or cracked or also just because of loose gas capping.

  • Exhaust leak

If there is an exhaust leak then it can cause all kinds of problems for any vehicle and it will be quite obvious how such things can result in failed emission test.

An exhaust leak will not only just throw off your reading of oxygen sensor, it will mean the fumes will not be passing via the catalytic converter that changes them to less harmful emission.

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